U.S. patent application number 09/919198 was filed with the patent office on 2002-07-04 for coating compositions having improved adhesion, coated substrates and methods related thereto.
Invention is credited to Anderson, Lawrence G., Sadvary, Richard J., Tyebjee, Shiryn.
Application Number | 20020086168 09/919198 |
Document ID | / |
Family ID | 25441688 |
Filed Date | 2002-07-04 |
United States Patent
Application |
20020086168 |
Kind Code |
A1 |
Sadvary, Richard J. ; et
al. |
July 4, 2002 |
Coating compositions having improved adhesion, coated substrates
and methods related thereto
Abstract
Coating compositions are provided which include a polysiloxane
comprising at least one reactive functional group, at least one
material comprising at least one reactive functional group, and at
least one boron-containing compound. Also provided are multi-layer
composite coatings formed from a basecoat deposited from a
pigmented coating composition and a topcoat applied over the
basecoat, the topcoat deposited from the aforementioned coating
composition. Methods for repairing a multi-layer composite coating
and coated substrates are also provided. The compositions of the
invention provide highly scratch resistant coatings, particularly
highly scratch resistant color-plus-clear coatings, which have
excellent intercoat adhesion to subsequently applied coating
layers.
Inventors: |
Sadvary, Richard J.;
(Pittsburgh, PA) ; Anderson, Lawrence G.;
(Pittsburgh, PA) ; Tyebjee, Shiryn; (Allison Park,
PA) |
Correspondence
Address: |
PPG Industries, Inc.
One PPG Place
Pittsburgh
PA
15272
US
|
Family ID: |
25441688 |
Appl. No.: |
09/919198 |
Filed: |
July 31, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09919198 |
Jul 31, 2001 |
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09629423 |
Jul 31, 2000 |
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09919198 |
Jul 31, 2001 |
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09629443 |
Jul 31, 2000 |
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09489043 |
Jan 21, 2000 |
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09365069 |
Jul 30, 1999 |
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09919198 |
Jul 31, 2001 |
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09629443 |
Jul 31, 2000 |
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09629443 |
Jul 31, 2000 |
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09489132 |
Jan 21, 2000 |
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09489132 |
Jan 21, 2000 |
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09365069 |
Jul 30, 1999 |
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60171899 |
Dec 23, 1999 |
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60171898 |
Dec 23, 1999 |
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Current U.S.
Class: |
428/447 ;
524/588 |
Current CPC
Class: |
C09D 7/00 20130101; C09D
183/04 20130101; C08K 3/36 20130101; C09D 7/68 20180101; C08K
2201/011 20130101; C08J 3/20 20130101; Y10T 428/31663 20150401;
C09D 7/67 20180101; C08K 3/01 20180101; C09D 7/62 20180101; B82Y
30/00 20130101; C09D 183/04 20130101; C08L 2666/54 20130101; C09D
183/04 20130101; C08L 2666/04 20130101; C08L 2666/54 20130101; C09D
183/04 20130101; C08L 2666/14 20130101; C08L 2666/54 20130101; C09D
183/04 20130101; C08L 2666/28 20130101; C08L 2666/54 20130101 |
Class at
Publication: |
428/447 ;
524/588 |
International
Class: |
B32B 009/04; C08J
003/00 |
Claims
Therefore we claim:
1. A coating composition formed from components comprising: (a) at
least one polysiloxane comprising at least one reactive functional
group, the polysiloxane comprising at least one of the following
structural units (I):
R.sup.1.sub.nR.sup.2.sub.mSiO.sub.(4-n-m)/.sub.2 (I) wherein each
R.sup.1, which may be identical or different, represents H, OH, a
monovalent hydrocarbon group or a monovalent siloxane group; each
R.sup.2, which may be identical or different, represents a group
comprising at least one reactive functional group, wherein m and n
fulfill the requirements of 0<n<4, 0<m<4 and
2.ltoreq.(m+n)<4; (b) at least one reactant comprising at least
one functional group that is reactive with the reactive functional
group of the polysiloxane (a); and (c) at least one
boron-containing compound selected from boric acid, boric acid
equivalents, and mixtures thereof, wherein each component is
different.
2. A coating composition according to claim 1, further comprising
at least one functional group-containing film-forming polymer.
3. A coating composition according to claim 1, wherein each
R.sup.2, which may be identical or different, represents a group
comprising at least one reactive functional group selected from a
hydroxyl group, a carboxyl group, an isocyanate group, a blocked
isocyanate group, a primary amine group, a secondary amine group,
an amide group, a carbamate group, a urea group, a urethane group,
a vinyl group, an unsaturated ester group, a maleimide group, a
fumarate group, an anhydride group, a hydroxy alkylamide group, and
an epoxy group.
4. A coating composition according to claim 1, wherein the
polysiloxane (a) comprises at least two reactive functional
groups.
5. A coating composition according to claim 1, wherein at least one
R.sup.2 group represents a group comprising at least one reactive
functional group selected from a hydroxyl group and a carbamate
group.
6. A coating composition according to claim 5, wherein at least one
R.sup.2 group represents a group comprising at least two reactive
functional groups selected from a hydroxyl group and a carbamate
group.
7. A coating composition according to claim 1, wherein at least one
R.sup.2 group represents a group comprising an oxyalkylene group
and at least two hydroxyl groups.
8. A coating composition according to claim 1, wherein the
polysiloxane has the following structure (II) or (III): 5wherein: m
has a value of at least 1; m' ranges from 0 to 75; n ranges from 0
to 75; n' ranges from 0 to 75; each R, which may be identical or
different, is selected from H, OH, monovalent hydrocarbon groups,
monovalent siloxane groups, and mixtures of any of the foregoing;
and R' comprises the following structure (IV): --R.sup.3--X (IV)
wherein --R.sup.3 is selected from an alkylene group, an
oxyalkylene group, an alkylene aryl group, an alkenylene group, an
oxyalkenylene group, and an alkenylene aryl group; and X represents
a group which comprises at least one reactive functional group.
9. A coating composition according to claim 8, wherein (n +m)
ranges from 2 to 9.
10. A coating composition according to claim 9, wherein (n +m)
ranges from 2 to 3.
11. A coating composition according to claim 8, wherein (n'+m')
ranges from 2 to 9.
12. A coating composition according to claim 11, wherein (n'+m')
ranges from 2 to 3.
13. A coating composition according to claim 8, wherein X
represents a group which comprises at least one reactive functional
group selected from at least one of a hydroxyl group, a carboxyl
group, an isocyanate group, a blocked isocyanate group, a primary
amine group, a secondary amine group, an amide group, a carbamate
group, a urea group, a urethane group, a vinyl group, an
unsaturated ester group, a maleimide group, a fumarate group, an
anhydride group, a hydroxy alkylamide group, and an epoxy
group.
14. A coating composition according to claim 13, wherein X
represents a group comprising at least one reactive functional
group selected from a hydroxyl group and a carbamate group.
15. A coating composition according to claim 13, wherein X
represents a group comprising at least two hydroxyl groups.
16. A coating composition according to claim 1, wherein the at
least one polysiloxane (a), when added to the other components that
form the composition, is present in the composition in an amount
ranging from 0.01 to 90 weight percent based on total weight of
resin solids of the components from which the composition is
formed.
17. A coating composition according to claim 16, wherein the at
least one polysiloxane (a) is present in an amount of at least 2
weight percent.
18. A coating composition according to claim 16, wherein the at
least one polysiloxane (a) is present in an amount of at least 5
weight percent.
19. A coating composition according to claim 16, wherein the at
least one polysiloxane (a) is present in an amount of at least 10
weight percent.
20. A coating composition according to claim 16, wherein the at
least one polysiloxane (a) is present in an amount of at least 20
weight percent.
21. A coating composition according to claim 2, wherein the at
least one reactive functional group-containing film-forming polymer
is selected from at least one of polyether polymers, polyester
polymers, acrylic polymers, silicon-based polymers, and
polyurethane polymers.
22. A coating composition according to claim 2, wherein the
film-forming polymer comprises at least one reactive functional
group selected from a hydroxyl group, a carboxyl group, an
isocyanate group, a blocked isocyanate group, a primary amine
group, a secondary amine group, an amide group, a carbamate group,
a urea group, a urethane group, a vinyl group, an unsaturated ester
group, a maleimide group, a fumarate group, an anhydride group, a
hydroxy alkylamide group, and an epoxy group.
23. A coating composition according to claim 2, wherein the
film-forming polymer comprises at least one reactive functional
group selected from a hydroxyl group, a carboxyl group, an
isocyanate group, a carbamate group, and an epoxy group.
24. A coating composition according to claim 23, wherein the
film-forming polymer comprises a n acrylic polymer having reactive
functional groups selected from a hydroxyl group and a carbamate
group.
25. A coating composition according to claim 2, wherein the at
least one reactive functional group-containing film-forming polymer
when added to the other components that form the composition, is
present in the composition in an amount ranging from 2 to 80 weight
percent based on total weight of resin solids of the components
from which the composition is formed.
26. A coating composition according to claim 1, wherein the at
least one reactant (b) is selected from at least one curing
agent.
27. A coating composition according to claim 26, wherein the at
least one curing agent is selected from at least one of an
aminoplast resin, a polyisocyanate, a blocked isocyanate, a
polyepoxide, a polyacid, and a polyol.
28. A coating composition according to claim 27, wherein the at
least one curing agent comprises a polyisocyanate or a blocked
isocyanate compound.
29. A coating composition according to claim 27, wherein the at
least one curing agent comprises a mixture of a polyisocyanate and
an aminoplast resin.
30. A coating composition according to claim 26, wherein the curing
agent, when added to the other components that form the
composition, is present in an amount ranging from 2 to 65 weight
percent based on total weight of resin solids of the components
from which the composition is formed.
31. A coating composition according to claim 1, wherein the
boron-containing compound (c) is selected from at least one of
boric acid, a boric acid ester, and mixtures thereof.
32. A coating composition according to claim 31, wherein the
boron-containing compound comprises boric acid.
33. A coating composition according to claim 31, wherein said
boron-containing compound comprises a boric acid ester selected
from at least one of triisopropyl borate, trimethyl borate,
triphenyl borate trimethoxyboroxine, polysiloxane borate, acrylic
borate, and mixtures thereof and mixtures thereof.
34. A coating composition according to claim 31, wherein said
boron-containing compound comprises a boric acid ester derivative
selected from at least one of triethanolamineborate,
triethanolamine borate, mannitol borate, n-propranol amine borate,
trimetholpropane borate, glycerol borate, and mixtures thereof.
35. A coating composition according to claim 31, wherein the
boron-containing compound comprises a reaction product formed from
the following reactants: (A) at least one polysiloxane comprising
at least one of the following structural units (I):
R.sup.1.sub.nR.sup.2.sub.mSiO.- sub.(4-n-m)/2 (I) wherein each
R.sup.1, which may be identical or different, represents H, OH, a
monovalent hydrocarbon group or a monovalent siloxane group; each
R.sup.2, which may be identical or different, represents a group
comprising at least one reactive functional group, wherein m and n
fulfill the requirements of 0<n<4, 0<m<4 and
2.ltoreq.(m+n)<4; and (B) at least one boron-containing compound
selected from at least one of boric acid, boric acid equivalents,
and mixtures thereof.
36. A coating composition according to claim 35, wherein the
polysiloxane (A) comprises at least two reactive functional
groups.
37. A coating composition according to claim 35, wherein at least
one R.sup.2 group represents a group comprising at least one
hydroxyl group.
38. A coating composition according to claim 35, wherein at least
one R.sup.2 group represents a group comprising at least two
hydroxyl groups.
39. A coating composition according to claim 38, wherein at least
one R.sup.2 group represents a group comprising an oxyalkylene
group and at least two hydroxyl groups.
40. A coating composition according to claim 35, wherein the
polysiloxane (A) has the following structure (II) or (III):
6wherein: m has a value of at least 1; m' ranges from 0 to 75; n
ranges from 0 to 75; n' ranges from 0 to 75; each R, which may be
identical or different, is selected from H, OH, monovalent
hydrocarbon groups, monovalent siloxane groups, and mixtures of any
of the foregoing; and R.sup.a comprises the following structure
(IV): --R.sup.3--X (IV) wherein --R.sup.3 is selected from an
alkylene group, an oxyalkylene group, an alkylene aryl group, an
alkenylene group, an oxyalkenylene group, and an alkenylene aryl
group; and X represents a group which comprises at least one
reactive functional group.
41. A coating composition according to claim 40, wherein (n+m)
ranges from 2 to 9.
42. A coating composition according to claim 41, wherein (n+m)
ranges from 2 to 3.
43. A coating composition according to claim 40, wherein (n'+m')
ranges from 2 to 9.
44. A coating composition according to claim 43, wherein (n'+m')
ranges from 2 to 3.
45. A coating composition according to claim 40, wherein X
represents a group which comprises at least one reactive functional
group selected from a hydroxyl group, a carboxyl group, a primary
amine group, a secondary amine group, an amide group, a carbamate
group, a urea group, an anhydride group, a hydroxy alkylamide
group, and an epoxy group.
46. A coating composition according to claim 40, wherein X
represents a group comprising at least two hydroxyl groups.
47. A coating composition according to claim 1, wherein the at
least one boron-containing compound (c), when added to the other
components that form the composition, is present in the composition
in an amount sufficient to provide an amount of boron ranging from
0.001 to 5 weight percent based on total weight of resin solids of
the components from which the composition is formed.
48. A coating composition according to claim 1, wherein the
components from which the coating composition is formed further
comprise a plurality of particles which are different from
components (a), (b) and (c).
49. A coating composition according to claim 48, wherein the
plurality of particles are selected from inorganic particles,
composite particles, and mixtures thereof.
50. A coating composition according to claim 48, wherein the
particles are selected from fumed silica, amorphous silica,
colloidal silica, alumina, colloidal alumina, titanium dioxide,
cesium oxide, yttrium oxide, colloidal yttria, zirconia, colloidal
zirconia and mixtures of any of the foregoing.
51. A coating composition according to claim 50, wherein the
particles comprise colloidal silica.
52. A coating composition according to claim 48, wherein the
particles are surface treated.
53. A coating composition according to claim 48, wherein the
particles have an average particle size of less than 100 microns
prior to incorporation into the composition.
54. A coating composition according to claim 48, wherein the
particles have an average particle size ranging from 1 to less than
1000 nanometers prior to incorporation into the composition.
55. A coating composition according to claim 54, wherein the
particles have an average particle size ranging from 1 to 100
nanometers prior to incorporation into the composition.
56. A coating composition according to claim 55, wherein the
particles have an average particle size ranging from 5 to 50
nanometers prior to incorporation into the composition.
57. A coating composition according to claim 48, wherein the
particles, when added to the other components that form the
composition, are present in the composition in an amount ranging
from 0.01 to 75 weight percent based on total weight of the resin
solids of the components from which the composition is formed.
58. A coating composition according to claim 57, wherein the
particles are present in an amount of at least 0.1 weight
percent.
59. A coating composition according to claim 58, wherein the
particles are present in an amount of at least 0.5 weight
percent.
60. A coating composition according to claim 58, wherein the
particles are present in an amount of less than 20 weight
percent.
61. A coating composition according to claim 59, wherein the
particles are present in an amount of less than 10 weight
percent.
62. A coating composition formed from components comprising: (a) at
least one polysiloxane comprising at least one reactive functional
group, the polysiloxane comprising at least one of the following
structural units (I): R.sup.1.sub.nR.sup.2.sub.mSiO.sub.(4-n-m)/2
(I) wherein each R.sup.1, which may be identical or different,
represents H, OH, a monovalent hydrocarbon group or a monovalent
siloxane group; each R.sup.2, which may be identical or different,
represents a group comprising at least one reactive functional
group selected from a hydroxyl group and a carbamate group, wherein
m and n fulfill the requirements of 0<n<4, 0<m<4 and
2<(m+n)<4; (b) at least one reactant comprising at least one
curing agent having at least one functional group reactive with the
functional group of the polysiloxane (a), the curing agent selected
from at least one of a polyisocyanate, a blocked isocyanate, and an
aminoplast resin; (c) at least one boron-containing compound
selected from boric acid and; (d) a plurality of particles selected
from inorganic particles, composite particles, and mixtures
thereof, wherein each component is different.
63. A coating composition formed from components comprising: (a) at
least one polysiloxane comprising at least one reactive functional
group, the polysiloxane comprising at least one of the following
structural units (I): R.sup.1.sub.nR.sup.2.sub.mSiO.sub.(4-n-m)/2
(I) wherein each R.sup.1, which may be identical or different,
represents H, OH, a monovalent hydrocarbon group or a monovalent
siloxane group; each R.sup.2, which may be identical or different,
represents a group comprising at least one reactive functional
group selected from a hydroxyl group and a carbamate group, wherein
m and n fulfill the requirements of 0<n<4, 0<m<4 and
2.ltoreq.(m+n)<4; (b) at least one reactant comprising at least
one curing agent having at least one functional group reactive with
the functional group of the polysiloxane (a), the curing agent
selected from at least one of a polyisocyanate, a blocked
isocyanate, and an aminoplast resin; (c) at least one
boron-containing compound selected from boric acid, boric acid
equivalents, and mixtures thereof; (d) a plurality of particles
selected from inorganic particles, composite particles, and
mixtures thereof; and (e) at least one film-forming polymer
selected from polyether polymers, polyester polymers, acrylic
polymers and polyurethane polymers, said film-forming polymer
having functional groups reactive with the functional groups of (a)
and/or (b), wherein each component is different.
64. A coating composition formed from components comprising: (a) at
least one polysiloxane having the following structure (II) or
(III): 7wherein: m has a value of at least 1; m' ranges from 0 to
75; n ranges from 0 to 75; n' ranges from 0 to 75; each R, which
may be identical or different, is selected from H, OH, monovalent
hydrocarbon groups, monovalent siloxane groups, and mixtures of any
of the foregoing; and R.sup.a comprises the following structure
(IV): --R.sup.3--X (IV) wherein --R.sup.3 is selected from an
alkylene group, an oxyalkylene group, an alkylene aryl group, an
alkenylene group, an oxyalkenylene group, and an alkenylene aryl
group; and X represents a group which comprises at least one
reactive functional group selected from a hydroxyl group and a
carbamate group. (b) at least one reactant comprising at least one
curing agent having at least one functional group reactive with the
at least one functional group of the polysiloxane (a), the curing
agent selected from at least one of a polyisocyanate, a blocked
isocyanate, and an aminoplast resin; (c) at least one
boron-containing compound selected from boric acid, boric acid
equivalents, and mixtures thereof; (d) a plurality of inorganic
particles selected from fumed silica, amorphous silica, colloidal
silica, alumina, colloidal alumina, titanium dioxide, cesium oxide,
yttrium oxide, colloidal yttria, zirconia, colloidal zirconia and
mixtures of any of the foregoing, and mixtures thereof; and (e) at
least one film-forming acrylic polymer having reactive functional
groups selected from hydroyxl groups and carbamate groups, wherein
each component is different.
65. A multi-layer composite coating comprising a base coat
deposited on a substrate from a film-forming base coating
composition and a top coat deposited over at least a portion of the
base coat, said top coat formed from a film-forming top coating
composition formed from components comprising: (a) at least one
polysiloxane comprising at least one reactive functional group, the
polysiloxane comprising at least one of the following structural
units (I): R.sup.1.sub.nR.sup.2.sub.mSiO.sub.(4-- n-m)/.sub.2 (I)
wherein each R.sup.1, which may be identical or different,
represents H, OH, a monovalent hydrocarbon group or a monovalent
siloxane group; each R.sup.2, which may be identical or different,
represents a group comprising at least one reactive functional
group, wherein m and n fulfill the requirements of 0<n<4,
0<m<4 and 2.ltoreq.(m+n)<4; (b) at least one reactant
comprising at least one functional group that is reactive with the
reactive functional group of the polysiloxane (a); and (c) at least
one boron-containing compound selected from boric acid, boric acid
equivalents, and mixtures thereof, wherein each component is
different.
66. A multi-layer composite coating according to claim 65, wherein
the top coating composition further comprises at least one
functional group-containing film-forming polymer.
67. A multi-layer composite coating according to claim 65, wherein
each R.sup.2, which may be identical or different, represents a
group comprising at least one reactive functional group selected
from a hydroxyl group, a carboxyl group, an isocyanate group, a
blocked isocyanate group, a primary amine group, a secondary amine
group, an amide group, a carbamate group, a urea group, a urethane
group, a vinyl group, an unsaturated ester group, a maleimide
group, a fumarate group, an anhydride group, a hydroxy alkylamide
group, and an epoxy group.
68. A multi-layer composite coating according to claim 65, wherein
at least one R.sup.2 group represents a group comprising at least
two reactive functional groups selected from a hydroxyl group and a
carbamate group.
69. A multi-layer composite coating according to claim 66, wherein
the polysiloxane (a) has the following structure (II) or (III):
8wherein: m has a value of at least 1; m' ranges from 0 to 75; n
ranges from 0 to 75; n' ranges from 0 to 75; each R, which may be
identical or different, is selected from H, OH, monovalent
hydrocarbon groups, monovalent siloxane groups, and mixtures of any
of the foregoing; and R.sup.a comprises the following structure
(IV): --R.sup.3--X (IV) wherein --R.sup.3 is selected from an
alkylene group, an oxyalkylene group, an alkylene aryl group, an
alkenylene group, an oxyalkenylene group, and an alkenylene aryl
group; and X represents a group which comprises at least one
reactive functional group.
70. A multi-layer composite coating according to claim 69, wherein
X represents a group which comprises at least one reactive
functional group selected from at least one of a hydroxyl group, a
carboxyl group, an isocyanate group, a blocked isocyanate group, a
primary amine group, a secondary amine group, an amide group, a
carbamate group, a urea group, a urethane group, a vinyl group, an
unsaturated ester group, a maleimide group, a fumarate group, an
anhydride group, a hydroxy alkylamide group, and an epoxy
group.
71. A multi-layer composite coating according to claim 70, wherein
X represents a group comprising at least one reactive functional
group selected from a hydroxyl group and a carbamate group.
72. A multi-layer composite coating according to claim 70, wherein
X represents a group comprising at least two hydroxyl groups.
73. A multi-layer composite coating according to claim 1, wherein
the at least one polysiloxane (a), when added to the other
components that form the composition, is present in the composition
in an amount ranging from 0.01 to 90 weight percent based on total
weight of resin solids of the components from which the composition
is formed.
74. A multi-layer composite coating composition according to claim
2, wherein the at least one reactive functional group-containing
film-forming polymer is selected from at least one of polyether
polymers, polyester polymers, acrylic polymers, silicon-based
polymers, and polyurethane polymers.
75. A multi-layer composite coating composition according to claim
2, wherein the film-forming polymer comprises at least one reactive
functional group selected from a hydroxyl group, a carboxyl group,
an isocyanate group, a blocked isocyanate group, a primary amine
group, a secondary amine group, an amide group, a carbamate group,
a urea group, a urethane group, a vinyl group, an unsaturated ester
group, a maleimide group, a fumarate group, an anhydride group, a
hydroxy alkylamide group, and an epoxy group.
76. A multi-layer composite coating according to claim 2, wherein
the film-forming polymer comprises at least one reactive functional
group selected from a hydroxyl group, a carboxyl group, an
isocyanate group, a carbamate group, and an epoxy group.
77. A multi-layer composite coating according to claim 76, wherein
the film-forming polymer comprises an acrylic polymer having
reactive functional groups selected from a hydroxyl group and a
carbamate group.
78. A multi-layer composite coating according to claim 2, wherein
the at least one reactive functional group-containing film-forming
polymer when added to the other components that form the
composition, is present in the composition in an amount ranging
from 2 to 80 weight percent based on total weight of resin solids
of the components from which the composition is formed.
79. A multi-layer composite coating according to claim 1, wherein
the at least one reactant (b) is selected from at least one curing
agent.
80. A multi-layer composite coating according to claim 79, wherein
the at least one curing agent is selected from at least one of an
aminoplast resin, a polyisocyanate, a blocked isocyanate compound,
a polyepoxide, a polyacid, and a polyol.
81. A multi-layer composite coating according to claim 80, wherein
the at least one curing agent comprises a polyisocyanate and/or
blocked isocyanate compound.
82. A multi-layer composite coating according to claim 80, wherein
the at least one curing agent comprises a mixture of a
polyisocyanate and an aminoplast resin.
83. A multi-layer composite coating according to claim 79, wherein
the curing agent, when added to the other components that form the
composition, is present in an amount ranging from 2 to 65 weight
percent based on total weight of resin solids of the components
from which the composition is formed.
84. A multi-layer composite coating according to claim 1, wherein
the boron-containing compound (c) is selected from at least one of
boric acid, boric acid ester, and mixtures thereof.
85. A multi-layer composite coating according to claim 84, wherein
the boron-containing compound comprises boric acid.
86. A multi-layer composite coating according to claim 84, wherein
said boron-containing compound comprises a boric acid ester
selected from at least one of triisopropyl borate, trimethyl
borate, triphenyl borate trimethoxyboroxine, polysiloxane borate,
acrylic borate, and mixtures thereof.
87. A multi-layer composite coating according to claim 84, wherein
the boron-containing compound comprises a reaction product of the
following reactants: (A) at least one polysiloxane comprising at
least one of the following structural units (I):
R.sup.1.sub.nR.sup.2.sub.mSiO.sub.(4-n-m)- /2 (I) wherein each
R.sup.1, which may be identical or different, represents H, OH, a
monovalent hydrocarbon group or a monovalent siloxane group; each
R.sup.2, which may be identical or different, represents a group
comprising at least one reactive functional group, wherein m and n
fulfill the requirements of 0<n<4, 0<m<4 and
2.ltoreq.(m+n)<4; and (B) at least one boron-containing compound
selected from at least one of boric acid, boric acid equivalents,
and mixtures thereof.
88. A multi-layer composite coating according to claim 87, wherein
at least one R.sup.2 represents a group comprising at least one
hydroxyl group.
89. A multi-layer composite coating according to claim 87, wherein
at least one R.sup.2 represents a group comprising at least two
hydroxyl groups.
90. A multi-layer composite coating according to claim 87, wherein
the polysiloxane (A) has the following structure (II) or (III):
9wherein: m has a value of at least 1; m' ranges from 0 to 75; n
ranges from 0 to 75; n' ranges from 0 to 75; each R, which may be
identical or different, is selected from H, OH, monovalent
hydrocarbon groups, monovalent siloxane groups, and mixtures of any
of the foregoing; and R.sup.a comprises the following structure
(IV): --R.sup.3--X (IV) wherein --R.sup.3 is selected from an
alkylene group, an oxyalkylene group, an alkylene aryl group, an
alkenylene group, an oxyalkenylene group, and an alkenylene aryl
group; and X represents a group which comprises at least one
reactive functional group.
91. A multi-layer composite coating according to claim 90, wherein
X represents a group which comprises at least one reactive
functional group selected from a hydroxyl group, a carboxyl group,
a primary amine group, a secondary amine group, an amide group, a
carbamate group, a urea group, an anhydride group, a hydroxy
alkylamide group, and an epoxy group.
92. A multi-layer composite coating according to claim 90, wherein
X represents a group comprising at least two hydroxyl groups.
93. A multi-layer composite coating according to claim 1, wherein
the at least one boron-containing compound (c), when added to the
other components that form the top coating composition, is present
in the top coating composition in an amount sufficient to provide
an amount of boron ranging from 0.001 to 5 weight percent based on
total weight of resin solids of the components from which the top
coating composition is formed.
94. A multi-layer composite coating according to claim 1, wherein
the components from which the coating composition is formed further
comprise a plurality of particles which are different from
components (a), (b) and (c).
95. A multi-layer composite according to claim 94, wherein the
plurality of particles are selected from inorganic particles,
composite particles, and mixtures thereof.
96. A multi-layer composite coating according to claim 94, wherein
the particles are selected from fumed silica, amorphous silica,
colloidal silica, alumina, colloidal alumina, titanium dioxide,
cesium oxide, yttrium oxide, colloidal yttria, zirconia, colloidal
zirconia and mixtures of any of the foregoing.
97. A multi-layer composite coating according to claim 96, wherein
the particles comprise colloidal silica.
98. A multi-layer composite coating according to claim 94, wherein
the particles have an average particle size ranging from 1 to less
than 1000 nanometers prior to incorporation into the
composition.
99. A multi-layer composite coating according to claim 98, wherein
the particles have an average particle size ranging from 1 to 100
nanometers prior to incorporation into the composition.
100. A multi-layer composite coating according to claim 94, wherein
the particles, when added to the other components that form the
composition, are present in the composition in an amount ranging
from 0.01 to 75 weight percent based on total weight of the resin
solids of the components from which the composition is formed.
101. A multi-layer composite coating according to claim 100,
wherein the particles are present in an amount of at least 0.1
weight percent.
102. A multi-layer composite coating according to claim 101,
wherein the particles are present in an amount of less than 20
weight percent.
103. A multi-layer composite coating comprising a base coat
deposited on a substrate from a film-forming base coating
composition, and a top coat deposited over at least a portion of
the base coat, said top coat deposited from a film-forming top
coating composition formed from components comprising: (a) at least
one polysiloxane comprising at least one reactive functional group,
the polysiloxane comprising at least one of the following
structural units (I): R.sup.1.sub.nR.sup.2.sub.mSiO.sub.- (4-n-m)/2
(I) wherein each R.sup.1, which may be identical or different,
represents H, OH, a monovalent hydrocarbon group or a monovalent
siloxane group; each R.sup.2, which may be identical or different,
represents a group comprising at least one reactive functional
group selected from a hydroxyl group and a carbamate group, wherein
m and n fulfill the requirements of 0<n<4, 0<m<4 and
2.ltoreq.(m+n)<4; (b) at least one reactant comprising at least
one curing agent having at least one functional group reactive with
the functional group of the polysiloxane (a), the curing agent
selected from at least one of a polyisocyanate, a blocked
isocyanate, and an aminoplast resin; (c) at least one
boron-containing compound selected from boric acid, boric acid
equivalents, and mixtures thereof; and (d) a plurality of particles
selected from inorganic particles, composite particles, and
mixtures thereof, wherein each component is different.
104. A multi-layer composite coating comprising a base coat
deposited on a substrate from a film-forming base coating
composition and a top coat deposited over at least a portion of the
base coat, said top coat deposited from a film-forming top coating
composition formed from components comprising: (a) at least one
polysiloxane comprising at least one reactive functional group, the
polysiloxane comprising at least one of the following structural
units (I): R.sup.1.sub.nR.sup.2.sub.mSiO.sub.- (4-n-m)/2 (I)
wherein each R.sup.1, which may be identical or different,
represents H, OH, a monovalent hydrocarbon group or a monovalent
siloxane group; each R.sup.2, which may be identical or different,
represents a group comprising at least one reactive functional
group selected from a hydroxyl group and a carbamate group, wherein
m and n fulfill the requirements of 0<n<4, 0<m<4 and
2.ltoreq.(m+n)<4; (b) at least one reactant comprising at least
one curing agent having at least one functional group reactive with
the functional group of the polysiloxane (a), the curing agent
selected from at least one of a polyisocyanate, a blocked
isocyanate, and an aminoplast resin; (c) at least one
boron-containing compound selected from boric acid, boric acid
equivalents, and mixtures thereof; (d) a plurality of particles
selected from inorganic particles, composite particles, and
mixtures thereof; and (e) at least one film-forming polymer
selected from polyether polymers, polyester polymers, acrylic
polymers silicon-based polymers, and polyurethane polymers, said
film-forming polymer having functional groups reactive with the
functional groups of (a) and/or (b), wherein each component is
different.
105. A multi-layer composite coating comprising a base coat
deposited on a substrate from a film-forming base coating
composition and a top coat deposited over at least a portion of the
base coat, said top coat deposited from a film-forming top coating
composition formed from components comprising: (a) at least one
polysiloxane having the following structure (II) or (III):
10wherein: m has a value of at least 1; m' ranges from 0 to 75; n
ranges from 0 to 75; n' ranges from 0 to 75; each R, which may be
identical or different, is selected from H, OH, monovalent
hydrocarbon groups, monovalent siloxane groups, and mixtures of any
of the foregoing; and R.sup.a comprises the following structure
(IV): --R.sup.3--X (IV) wherein --R.sup.3 is selected from an
alkylene group, an oxyalkylene group, an alkylene aryl group, an
alkenylene group, an oxyalkenylene group, and an alkenylene aryl
group; and X represents a group which comprises at least one
reactive functional group selected from a hydroxyl group and a
carbamate group. (b) at least one reactant comprising at least one
curing agent having at least one functional group reactive with the
at least one functional group of the polysiloxane (a), the curing
agent selected from at least one of a polyisocyanate, a blocked
isocyanate, and an aminoplast resin; (c) at least one
boron-containing compound selected from boric acid, borate acid
equivalents, and mixtures thereof; (d) a plurality of inorganic
particles selected from fumed silica, amorphous silica, colloidal
silica, alumina, colloidal alumina, titanium dioxide, cesium oxide,
yttrium oxide, colloidal yttria, zirconia, colloidal zirconia and
mixtures of any of the foregoing, and mixtures thereof; and (e) at
least one film-forming acrylic polymer having reactive functional
groups selected from hydroyxl groups and carbamate groups, wherein
each component is different.
106. A method of repairing a multi-layer composite coating
comprising a base coat formed on a substrate from a film-forming
base coating composition and a first top coat deposited over at
least a portion of the base coat, said first top coat formed from a
first film-forming top coating composition formed from components
comprising: (a) at least one polysiloxane comprising at least one
reactive functional group, the polysiloxane comprising at least one
of the following structural units (I):
R.sup.1.sub.nR.sup.2.sub.mSiO.sub.(4-n-m)/2 (I) wherein each
R.sup.1, which may be identical or different, represents H, OH, a
monovalent hydrocarbon group or a monovalent siloxane group; each
R.sup.2, which may be identical or different, represents a group
comprising at least one reactive functional group, wherein m and n
fulfill the requirements of 0<n<4, 0<m<4 and
2.ltoreq.(m+n)<4; (b) at least one reactant comprising at least
one functional group that is reactive with the reactive functional
group of the polysiloxane (a); and (c) at least one
boron-containing compound selected from boric acid, boric acid
equivalents, and mixtures thereof, wherein each component is
different, the method comprising: locating an area of the composite
coating which is flawed, applying a repair top coat film-forming
composition to the flawed area after the flawed area has been
prepared for repairing, wherein the repair top coat film-forming
composition comprises a film-forming composition which is the same
or different from the first top coat film-forming composition.
107. A method according to claim 106, wherein the boron-contaiining
compound (c) wherein the boron-containing compound comprises a
reaction product formed from the following reactants: (A) at least
one polysiloxane comprising at least one of the following
structural units (I): R.sup.1.sub.nR.sup.2.sub.mSiO.sub.(4-n-m)/2
(I) wherein each R.sup.1, which may be identical or different,
represents H, OH, a monovalent hydrocarbon group or a monovalent
siloxane group; each R.sup.2, which may be identical or different,
represents a group comprising at least one reactive functional
group, wherein m and n fulfill the requirements of 0<n<4,
0<m<4 and 2.ltoreq.(m+n)<4; and (B) at least one
boron-containing compound selected from at least one of boric acid,
boric acid equivalents, and mixtures thereof.
108. A method according to claim 106, wherein the first
film-forming top coating composition further comprises inorganic
particles selected from fumed silica, amorphous silica, colloidal
silica, alumina, colloidal alumina, titanium dioxide, cesium oxide,
yttrium oxide, colloidal yttria, zirconia, colloidal zirconia and
mixtures of any of the foregoing, and mixtures thereof.
109. A coating composition formed from components comprising: (a)
at least one polysiloxane comprising at least one reactive
functional group, the polysiloxane comprising at least one of the
following structural units (I):
R.sup.1.sub.nR.sup.2.sub.mSiO.sub.(4-n-m)/2 (I) wherein each
R.sup.1, which may be identical or different, represents H, OH, a
monovalent hydrocarbon group or a monovalent siloxane group; each
R.sup.2, which may be identical or different, represents a group
comprising at least one reactive functional group, wherein m and n
fulfill the requirements of 0<n<4, 0<m<4 and
2.ltoreq.(m+n)<4; (c) at least one reactant comprising at least
one functional group that is reactive with the reactive functional
group of the polysiloxane (a); and (c) at least one compound
selected from borates, aluminates, titanates, zirconates,
silicates, siloxanes, silanes, and mixtures thereof, wherein each
component is different.
110. A coating composition according to claim 109, wherein the
compound (c) comprises at least one of a borate and an
aluminate.
111. A coating composition according to claim 110, wherein the
compound (c) comprises aluminum alkoxide.
112. A coated substrate comprising a substrate and a cured coating
over at least a portion of the substrate, the cured coating formed
from the coating composition of claim 1.
113. A coated substrate comprising a substrate and a cured coating
over at least a portion of the substrate, the cured coating formed
from the coating composition of claim 2.
114. A coated substrate comprising a substrate and a cured
multi-layer composite coating over at least a portion of the
substrate, the cured multilayer composite coating comprising a base
coat over at least a portion of the substrate formed from a
film-forming base coating composition and a top coat over at least
a portion of the base coat, the top coat formed from the coating
composition of claim 1.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part application of
U.S. patent application Ser. No. 09/629,423, filed Jul. 31, 2000,
which is a continuation-in-part of U.S. patent application Ser. No.
09/489,043, filed Jan. 21, 2000, which is a continuation-in-part of
U.S. patent application Ser. No. 09/365,069, filed Jul. 30, 1999.
U.S. patent application Ser. No. 09/489,043 claims the benefit of
priority from Provisional Patent Application Ser. No. 60/171,899,
filed Dec. 23, 1999.
[0002] This application is also a continuation-in-part application
of U.S. Pat. application Ser. No. 09/629,433, filed Jul. 31, 2000,
which is a continuation-in-part of U.S. patent application Ser. No.
09/489,132, filed Jan. 21, 2000, which is a continuation-in-part of
U.S. patent application Ser. No. 09/365,069, filed Jul. 30, 1999.
U.S. patent application Ser. No. 09/489,132 claims the benefit of
priority from Provisional Patent Application Ser. No. 60/171,898,
filed Dec. 23, 1999.
FIELD OF THE INVENTION
[0003] Certain embodiments of the present invention are directed to
coating compositions comprising at least one reactive functional
group-containing polysiloxane, at least one reactant comprising at
least one functional group that is reactive with the functional
group(s) of the polysiloxane, and at least one boron-containing
compound selected from boric acid, boric acid equivalents and
mixtures thereof. Other embodiments of the present invention are
directed to cured coatings formed from the foregoing coating
compositions. Further embodiments are directed to substrates coated
with the aforementioned compositions.
BACKGROUND OF THE INVENTION
[0004] Color-plus-clearcoating systems involving the application of
a colored or pigmented basecoat to a substrate followed by
application of a transparent or clearcoat over the basecoat have
become increasingly popular as original finishes for a number of
consumer products including, for example, automotive vehicles. The
color-plus-clearcoating systems have outstanding appearance
properties such as gloss and distinctness of image, due in large
part to the clearcoat. Such color-plus-clearcoating systems have
become popular for use with automotive vehicles, aerospace
applications, floor coverings such as ceramic tiles and wood
flooring, packaging coatings and the like.
[0005] Topcoat coating compositions, particularly those used to
form the transparent clearcoat in color-plus-clear coating systems
for automotive applications, are subject to defects that occur
during the assembly process as well as damage from numerous
environmental elements. Such defects during the assembly process
include paint defects in the application or curing of the basecoat
or the clearcoat. Damaging environmental elements include acidic
precipitation, exposure to ultraviolet radiation from sunlight,
high relative humidity and high temperatures, defects due to
contact with objects causing scratching of the coated surface, and
defects due to impact with small, hard objects resulting in
chipping of the coating surface.
[0006] Further, elastomeric automotive parts and accessories, for
example, elastomeric bumpers and body side moldings, are typically
coated "off site" and shipped to automobile assembly plants. The
coating compositions applied to such elastomeric substrates are
typically formulated to be very flexible so the coating can bend or
flex with the substrate without cracking. To achieve the requisite
flexibility, coating compositions for use on elastomeric substrates
often are formulated to produce coatings with lower crosslink
densities or to include flexibilizing adjuvants which act to lower
the overall film glass transition temperature (Tg). While
acceptable flexibility properties can be achieved with these
formulating techniques, they also can result in softer films that
are susceptible to scratching. Consequently, great expense and care
must be taken to package the coated parts to prevent scratching of
the coated surfaces during shipping to automobile assembly
plants.
[0007] U.S. Pat. No. 6,235,858 B1 discloses carbamate and/or urea
functional polymers for use in coating compositions, especially
clear coating compositions for color-plus-clear coating systems.
Such polymers provide coatings with good resistance to damage
caused by acidic precipitation.
[0008] U.S. Pat. No. 5,853,809 discloses clearcoats in
color-plus-clear systems which have improved scratch resistance due
to the inclusion in the coating composition of inorganic particles
such as colloidal silicas which have been surface modified with a
reactive coupling agent via covalent bonding.
[0009] A number of patents disclose the use of a surface active
material, for example, a polysiloxane, in coating compositions to
improve mar resistance of the cured coatings. U.S. Pat. Nos.
5,939,491 and 6,225,434B1 disclose coating compositions comprising
organic polysiloxanes having reactive functional groups. These
polysiloxanes provide coatings with improved mar and scratch
resistance.
[0010] A number of patents disclose the use of boric acid in
polymeric compositions. For example, U.S. Pat. Nos. 5,951,747 and
6,059,867 discloses the use of boric acid and borates in
conjunction with a succinate in non-chromate, corrosion-inhibiting
coating compositions for improved adhesion to metallic surfaces.
Such compositions further include inhibitors such as phosphates,
phosphosilicates, silicates, titanates, and zinc salts. U.S. Pat.
No. 4,832,990 discloses a process for improving adhesion of
polyolefins to metal substrates comprising mechanical cleaning of
the metal surface, treating the metal surface with a water-alcohol
solution containing an alkoxysilane and boric acid, thermally
treating the acid treated substrate, and subsequently treating the
substrate with a polyolefin-based composition comprising zeolites
and carbon black pigment. U.S. Pat. No. 5,073,455 discloses a
thermoplastic laminated film which has improved adhesion to
hydrophilic polymers, hydrophobic polymers and inorganic
substances. The film comprise a base film of thermoplastic resin
and a layer formed on the base film comprising a composition of one
or more of water-soluble resins, water emulsified resins and
water-dispersible resins, and an organic boron polymer or a mixture
composed of an organic boron polymer and vinyl alcohol.
[0011] Multi-layer composite coatings are commonplace in modern
coating lines. For example, a typical automotive coating system can
include the sequential application of an electrodeposition primer,
a primer-surfacer, a color enhancing base coat, and a transparent
top coat. In some instances, the electrodeposition primer is
applied over a mill-applied weldable, thermosetting coating which
has been applied to the coiled steel metal substrate from which the
automobile body (or body parts, such as fenders, doors and hoods)
has been formed. Also, adhesive coatings, for example, windshield
adhesives, trim and molding adhesives and structural adhesives are
sometimes applied to the cured top coats where necessary. Due to
these multi-layer composite coating processes, it is necessary that
the previously applied coating layer have excellent intercoat or
interlayer adhesion to the subsequently applied coating
layer(s).
[0012] Although the aforementioned coating compositions exhibit
improvements for acid etch resistance and mar and scratch
resistance, such compositions may not be readily recoatable. That
is, when a subsequent coating is applied to the cured mar and
scratch resistant coating composition, the intercoat adhesion
between the cured coating and the subsequently applied coating can
be quite poor.
[0013] For example, as mentioned above, on most vehicle coating
lines the vehicle body is first given a corrosion inhibitive
electrodepositable primer coating commonly formed from a cationic
electrodepositable coating composition. This electrodeposition
primer is fully cured and, a primer-surfacer is typically applied
to the cured electrodeposition primer. The primer-surfacer serves
to enhance chip resistance of subsequently applied top coatings as
well as to ensure good appearance of the top coatings. The top
coats, either a monocoat or a color-plus-clear system, are then
applied to the cured primer-surfacer coating. While most top coats
have excellent intercoat adhesion to the primer-surfacer coating,
some top coating compositions inherently can exhibit intercoat
adhesion problems with some primer-surfacer coatings.
[0014] Also, due to the interest in cost-savings, there is recent
interest in the automotive coatings market in eliminating the
primer-surfacer step altogether. That is, the top coats can be
directly applied to the cured electrodeposition primer. In such
modified coating processes, the electrodeposition primer is
required to meet stringent durability and appearance
specifications. Moreover, the cured electrodepositable primer must
have excellent intercoat adhesion to the subsequently applied top
coats (either monocoats or color coats of a color-plus-clear
system).
[0015] On commercial automobile coating lines during application of
the coating system, certain portions of the line can experience
occasional process problems, for example, clearcoat applicator
malfunctions, or curing oven faults where temperatures are out of
specification. While the color coat typically is "flash cured" to
drive off solvent, but not fully cure the coating, once the clear
coating has been applied, the color-plus-clear coating system
typically is given a full cure (e.g., 250.degree. F. for 20
minutes) to simultaneously cure both the base coat and the top
coat. In instances where the clear coat application system is
malfunctioning, the auto body with the applied color coat will
continue through the clear coat applicator station and into the
clear coat curing oven, thereby fully curing the color coat. If
this occurs, some automobile manufacturers elect to reapply the
color coat over the fully cured color coat prior to application of
the clearcoat. In such situations, the fully cured color coat can
have poor intercoat adhesion with the subsequently applied color
coat, even though the compositions may be the same.
[0016] Also, windshields and other items such as trim moldings
typically are affixed to the body of a vehicle with an adhesive
material, typically a moisture-cured material containing isocyanate
group-containing polymers. Motor Vehicle Safety Standards (MVSS)
require that these adhesives have complete adhesion to both the
windshield and the coated substrate to which they are applied.
Similar adhesive compositions can be used as structural adhesives
as well. Such adhesives, for example, are commercially available
from Essex Specialty Products, Inc. of Auburn Hills, Michigan.
These adhesive products adhere well to many cured top coating
compositions used to coat vehicles such as automobiles. It is
known, however, that these adhesive materials often do not
completely adhere to some top coats, for example, those formed from
coating compositions based on carbamate and/or urea containing
polymers. This necessitates the application of a primer coating to
the cured carbamate and/or urea-based top coatings prior to
application of the windshield adhesive to ensure compliance with
the aforementioned Motor Vehicle Safety Standards. Such primer
coatings are typically based on moisture-curable polymers similar
to those comprising the adhesive. Use of such primer coatings has
proven to be effective, but primer coating application adds an
additional and expensive step to the windshield or trim
installation process.
[0017] Moreover, as discussed previously, during the assembly
process, the applied color-plus-clear coating can include surface
defects in the clear coat surface which requires repair. Some
automobile manufacturers elect to remove the defect and recoat the
repair area with the same clear coat composition. In this instance,
the cured clear coat must have excellent intercoat adhesion to the
subsequently applied clear coat. It is known, however, that some
clear coats when cured have poor intercoat adhesion with the
subsequently applied repair clear coat.
[0018] In view of the foregoing, there obviously remains a need in
the coating industry for coating compositions which have improved
properties such as acid etch resistance and mar and scratch
resistance while maintaining excellent intercoat or interlayer
adhesion to subsequently applied coatings and/or adhesives.
SUMMARY OF THE INVENTION
[0019] In one embodiment a coating composition formed from
components comprising (a) at least one polysiloxane comprising at
least one reactive functional group, the polysiloxane comprising at
least one of the following structural units (I):
R.sup.1.sub.nR.sup.2.sub.mSiO.sub.(4-n-m)/2 (I)
[0020] wherein each R.sup.1, which may be identical or different,
represents H, OH, a monovalent hydrocarbon group or a monovalent
siloxane group; each R.sup.2, which may be identical or different,
represents a group comprising at least one reactive functional
group, wherein m and n fulfill the requirements of 0<n<4,
0<m<4 and 2.ltoreq.(m+n)<4; (b) at least one reactant
comprising at least one functional group that is reactive with the
reactive functional group of the polysiloxane (a); and (c) at least
one compound selected from borates, aluminates, titanates,
zirconates, silicates, siloxanes, silanes and mixtures thereof,
wherein each component is different.
[0021] In one embodiment, the present invention provides a coating
composition formed from components comprising (a) at least one
polysiloxane comprising at least one reactive functional group, the
polysiloxane comprising at least one of the structural units (I) as
described above, wherein each R.sup.1, which may be identical or
different, represents H, OH, a monovalent hydrocarbon group or a
monovalent siloxane group; each R.sup.2, which may be identical or
different, represents a group comprising at least one reactive
functional group, wherein m and n fulfill the requirements of
0<n<4, 0<m<4 and 2.ltoreq.(m+n)<4; (b) at least one
reactant comprising at least one functional group that is reactive
with the reactive functional group of the polysiloxane (a); and (c)
at least one boron-containing compound selected from boric acid,
boric acid equivalents and mixtures thereof, wherein each component
is different.
[0022] In another embodiment, the present invention provides a
coating composition formed from components comprising (a) at least
one polysiloxane comprising at least one reactive functional group,
the polysiloxane comprising at least one of the structural units
(1), wherein each R.sup.1, which may be identical or different,
represents H, OH, a monovalent hydrocarbon group or a monovalent
siloxane group; each R.sup.2, which may be identical or different,
represents a group comprising at least one reactive functional
group selected from a hydroxyl group and a carbamate group, wherein
m and n fulfill the requirements of 0<n<4, 0<m<4 and
2.ltoreq.(m+n)<4; (b) at least one reactant comprising at least
one curing agent having at least one functional group reactive with
the functional group of the polysiloxane (a), the curing agent
selected from at least one of a polyisocyanate, a blocked
isocyanate, and an aminoplast resin; (c) at least one
boron-containing compound selected from boric acid, boric acid
equivalents, and mixtures thereof; and (d) a plurality of particles
selected from inorganic particles, composite particles, and
mixtures thereof, wherein each component is different.
[0023] The present invention also provides a coating composition
formed from components comprising (a) at least one polysiloxane
comprising at least one reactive functional group, the polysiloxane
comprising at least one of the structural units (I), wherein each
R.sup.1, which may be identical or different, represents H, OH, a
monovalent hydrocarbon group or a monovalent siloxane group; each
R.sup.2, which may be identical or different, represents a group
comprising at least one reactive functional group selected from a
hydroxyl group, and a carbamate group, wherein m and n fulfill the
requirements of 0<n<4, 0<m<4 and 2.ltoreq.(m+n)<4;
(b) at least one reactant comprising at least one curing agent
having at least one functional group reactive with the functional
group of the polysiloxane (a), the curing agent selected from at
least one of a polyisocyanate, a blocked isocyanate, and an
aminoplast resin; (c) at least one boron-containing compound
selected from boric acid and organic derivatives thereof; (d) a
plurality of particles selected from inorganic particles, composite
particles, and mixtures thereof; and (e) at least one film-forming
polymer selected from polyether polymers, polyester polymers,
acrylic polymers and polyurethane polymers, said film-forming
polymer having functional groups reactive with the functional
groups of (a) and/or (b), wherein each component is different.
[0024] A further embodiment of the present invention provides a
coating composition formed from components comprising (a) at least
one polysiloxane having the following structure (II) or (III):
1
[0025] wherein m has a value of at least 1; m' ranges from 0 to 75;
n ranges from 0 to 5; n' ranges from 0 to 75; each R, which may be
identical or different, is selected from H, OH, monovalent
hydrocarbon groups, monovalent siloxane groups, and mixtures of any
of the foregoing; and R.sup.a comprises the following structure
(IV):
--R.sup.3--X (IV)
[0026] wherein -R.sup.3 is selected from an alkylene group, an
oxyalkylene group, an alkylene aryl group, an alkenylene group, an
oxyalkenylene group, and an alkenylene aryl group; and X represents
a group which comprises at least one reactive functional group
selected from a hydroxyl group and a carbamate group; (b) at least
one reactant comprising at least one curing agent having at least
one functional group reactive with the at least one functional
group of the polysiloxane (a), the curing agent selected from at
least one of a polyisocyanate, a blocked isocyanate, and an
aminoplast resin; (c) at least one boron-containing compound
selected from boric acid, boric acid equivalents, and mixtures
thereof; (d) a plurality of inorganic particles selected from fumed
silica, amorphous silica, colloidal silica, alumina, colloidal
alumina, titanium dioxide, cesium oxide, yttrium oxide, colloidal
yttria, zirconia, colloidal zirconia and mixtures of any of the
foregoing, and mixtures thereof; and (e) at least one film-forming
acrylic polymer having reactive functional groups selected from
hydroxyl groups and carbamate groups, wherein each component is
different.
[0027] Additionally, multi-component composite coatings formed from
a basecoat deposited from a film-forming base coating composition
and a top coat which is applied over at least a portion of the
basecoat and which is formed from any of the foregoing coating
compositions is provided.
[0028] Another aspect of the present invention is a method of
repairing a multi-layer composite coating comprising a base coat
formed on a substrate from a film-forming base coating composition
and a first top coat deposited over at least a portion of the base
coat, the first top coat formed from a first film-forming top
coating composition comprising any of the foregoing coating
compositions, the method comprising: locating an area of the
composite coating which is flawed, applying a repair top coat
film-forming composition to the flawed area after the flawed area
has been prepared for repairing, wherein the repair top coat
film-forming composition comprises a film-forming composition which
is the same or different from the first top coat film-forming
composition.
[0029] Coated substrates comprising a substrate and having any of
the foregoing coating compositions coated over at least a portion
of the substrate also are provided by the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Other than in the operating examples, or where otherwise
indicated, all numbers expressing quantities of ingredients,
reaction conditions and so forth used in the specification and
claims are to be understood as being modified in all instances by
the term "about." Accordingly, unless indicated to the contrary,
the numerical parameters set forth in the following specification
and attached claims are approximations that may vary depending upon
the desired properties sought to be obtained by the present
invention. At the very least, and not as an attempt to limit the
application of the doctrine of equivalents to the scope of the
claims, each numerical parameter should at least be construed in
light of the number of reported significant digits and by applying
ordinary rounding techniques.
[0031] Notwithstanding that the numerical ranges and parameters
setting forth the broad scope of the invention are approximations,
the numerical values set forth in the specific examples are
reported as precisely as possible. Any numerical values, however,
inherently contain certain errors necessarily resulting from the
standard deviation found in their respective testing
measurements.
[0032] Also, it should be understood that any numerical range
recited herein is intended to include all sub-ranges subsumed
therein. For example, a range of "1 to 10" is intended to include
all sub-ranges between and including the recited minimum value of 1
and the recited maximum value of 10, that is, having a minimum
value equal to or greater than 1 and a maximum value of equal to or
less than 10.
[0033] As mentioned above, in one embodiment, the present invention
is directed to a coating composition formed from components
comprising (a) at least one polysiloxane comprising at least one
reactive functional group, the polysiloxane comprising at least one
of the following structural units (I):
R.sup.1.sub.nR.sup.2.sub.mSiO.sub.(4-n-m)/2 (I)
[0034] wherein each R.sup.1, which may be identical or different,
represents H, OH, a monovalent hydrocarbon group or a monovalent
siloxane group; each R.sup.2, which may be identical or different,
represents a group comprising at least one reactive functional
group, wherein m and n fulfill the requirements of 0<n<4,
0<m<4 and 2.ltoreq.(m+n)<4; (b) at least one reactant
comprising at least one functional group that is reactive with the
reactive functional group of the polysiloxane (a); and (c) at least
one compound selected from borates, aluminates, titanates,
zirconates, silicates, siloxanes, silanes and mixtures thereof,
wherein each component is different. Typically, the at least one
compound (c) is selected from at least one of a borate and an
aluminate. Examples of suitable borates are those discussed in
detail below. Examples of titanates suitable for use in the
compositions of the present invention include titanium
isopropoxide, isopropyl triostearoyl titanate,
dicyclo(dioct)pyrophosphato titanate, tetraisopropyl
di(dioctyl)phosphito titanate. Suitable aluminates include aluminum
alkoxides such as aluminum isoproxide, which is typically employed,
and aluminum acetylacetonate, Exemplary of a suitable silicate is
tetraethyl orthosilicate. Suitable siloxanes include
tetraisopropyldisiloxanes and tetramethylsiloxane. Suitable silanes
include tetramethyl silyl ethers.
[0035] In one embodiment of the present invention, a polysiloxane
(a) comprising one or more hydroxyl functional groups is reacted
with an aluminum alkoxide such as aluminum triisopropoxide.
[0036] In one embodiment, the present invention provides a coating
composition formed from components comprising:(a) at least one
polysiloxane comprising at least one reactive functional group, the
polysiloxane comprising at least one of the following structural
units (I):
R.sup.1.sub.nR.sup.2.sub.mSiO.sub.(4-n-m)/2 (I)
[0037] wherein each R.sup.1, which may be identical or different,
represents H, OH, a monovalent hydrocarbon group or a monovalent
siloxane group; each R.sup.2, which may be identical or different,
represents a group comprising at least one reactive functional
group, wherein m and n fulfill the requirements of 0<n<4,
0<m<4 and 2.ltoreq.(m+n)<4; (b) at least one reactant
comprising at least one functional group that is reactive with the
reactive functional group of the polysiloxane (a); and (c) at least
one boron-containing compound selected from boric acid, boric acid
equivalents, organic derivatives thereof, and mixtures thereof,
wherein each component is different.
[0038] The at least one boron-containing compound (c) can be
selected from boric acid, boric acid equivalents, organic
derivatives thereof, and mixtures thereof. As used herein, in the
specification and in the claims, by "boric acid equivalents" is
meant any of the numerous boron-containing compounds which can
hydrolyze in aqueous media to form boric acid. Specific, but
non-limiting examples of boric acid equivalents include boron
oxides, for example, B.sub.2O.sub.3; boric acid esters such as
those obtained by the reaction of boric acid with an alcohol or
phenol.
[0039] Suitable boron-containing compounds include those selected
from boric acid, boric acid equivalents, and mixtures thereof. As
used herein and in the claims, by "boric acid equivalents" is meant
any of the numerous boron-containing compounds which can hydrolyze
in aqueous media to form boric acid. Specific, but non-limiting
examples of boric acid equivalents include boron oxides, for
example, B.sub.2O.sub.3; boric acid esters such as those obtained
by the reaction of boric acid with an alcohol or phenol, for
example, trimethyl borate, triethyl borate, tri-n-propyl borate,
tri-n-butyl borate, triphenyl borate, triisopropyl borate,
tri-t-amyl borate, tri-2-cyclohexylcyclohexyl borate,
triethanolamine borate, triisopropylamine borate, and
triisopropanolamine borate.
[0040] Additionally, other amino-containing borates and tertiary
amine salts of boric acid may be useful. Such boron-containing
compounds include, but are not limited to,
2-(beta-dimethylaminoisopropoxy)-4,5-dim-
ethyl-1,3,2-dioxaborolane,
2-(beta-diethylaminoethoxy)-4,4,6-trimethyl-1,3- ,2-dioxaborinane,
2-(beta-dimethylaminoethoxy)-4,4,6-trimethyl-1,3,2-dioxa- borinane,
2-(betha-diisopropylaminoethoxy-1,3,2-dioxaborinane,
2-(beta-dibutylaminoethoxy)-4-methyl-1,3,2-dioxaborinane,
2-(gamma-dimethylaminopropoxy)-1,3,6,9-tetrapxa-2-boracycloundecane,
and 2-(beta-dimethylaminoethoxy)-4,4-(4-hydorxybutyl)-1
,3,2-dioxaborolane.
[0041] Boric acid equivalents can also include metal salts of boric
acid (i.e., metal borates) provided that such metal borates can
readily dissociate in aqueous media to form boric acid. Suitable
examples of metal borates include, for example, calcium borate,
potassium borates such as potassium metaborate, potassium
tetraborate, potassium pentaborate, potassium hexaborate, and
potassium octaborate, sodium borates such as sodium perborate,
sodium metaborate, sodium diborate, sodium tetraborate, sodium
pentaborate, sodium perborate, sodium hexaborate, and sodium
octaborate, Likewise, ammonium borates can be useful.
[0042] Suitable boric acid equivalents can also include organic
oligomeric and polymeric compounds comprising boron-containing
moieties. Suitable examples include polymeric borate esters, such
as those formed by reacting an active hydrogen-containing polymer,
for example, a hydroxyl functional group-containing acrylic polymer
or polysiloxane polymer, with boric acid and/or a borate ester to
form a polymer having borate ester groups.
[0043] Polymers suitable for this purpose can include any of a
variety of active hydrogen-containing polymers such as those
selected from at least one of acrylic polymers, polyester polymers,
polyurethane polymers, polyether polymers and silicon-based
polymers. By "silicon-based polymers" is meant a polymer comprising
one or more --SiO-- units in the backbone. Such silicon-based
polymers can include hybrid polymers, such as those comprising
organic polymeric blocks with one or more --SiO-- units in the
backbone.
[0044] Examples of active hydrogen-containing polymers suitable for
this purpose include polymers comprising functional groups selected
from at least one of a hydroxyl group, an amine group an epoxy
group, a carbamate group, a urea group, and a carboxylic acid
group. In a particular embodiment of the present invention, the
boron-containing compound is formed by reacting boric acid and/or a
borate ester with at least one polymer selected from an acrylic
polyol, a polyester polyol, a polyurethane polyol, a polyether
polyol, a polysiloxane polyol and mixtures thereof.
[0045] In one embodiment of the present invention, the
boron-containing compound (c) comprises a polysiloxane borate ester
formed from the following reactants: (A) at least one polysiloxane
comprising at least one of the following structural units (I):
R.sup.1.sub.nR.sup.2.sub.mSiO.sub.(4-n-m)/2 (I)
[0046] wherein each R.sup.1, which may be identical or different,
represents H, OH, a monovalent hydrocarbon group or a monovalent
siloxane group; each R.sup.2, which may be identical or different,
represents a group comprising at least one reactive functional
group, wherein m and n fulfill the requirements of 0<n<4,
0<m<4 and 2.ltoreq.(m+n)<4; and (B) at least one
boron-containing compound selected from at least one of boric acid,
a boric acid equivalent, and mixtures thereof.
[0047] It should be understood that the "at least one polysiloxane
comprising at least one structural unit (I)" above is a polymer
that contains at least two Si atoms per molecule. As used herein,
the term "polymer" is meant to encompass oligomer, and includes
without limitation both homopolymers and copolymers. It should also
be understood that the at least one polysiloxane can include
linear, branched, dendritic or cyclic polysiloxanes.
[0048] Moreover, as used herein, "formed from" denotes open, e.g.,
"comprising," claim language. As such, it is intended that a
composition "formed from" a list of recited components be a
composition comprising at least these recited components, and can
further comprise other, nonrecited components, during the
composition's formation.
[0049] Also, as used herein, the term "reactive" refers to a
functional group that forms a covalent bond with another functional
group under conditions sufficient to cure the composition.
[0050] As used herein, the phrase "each component is different"
refers to components which do not have the same chemical structure
as other components in the composition.
[0051] Each of m and n depicted in the at least one structural unit
(I) above fulfill the requirements of 0<n<4, 0<m<4 and
2.ltoreq.(m+n)<4. When (m+n) is 3, the value represented by n
can be 2 and the value represented by m is 1. Likewise, when (m+n)
is 2, the value represented by each of n and m is 1.
[0052] As used herein, the term "cure" as used in connection with a
composition, e.g., "composition when cured," shall mean that any
crosslinkable components of the composition are at least partially
crosslinked. In certain embodiments of the present invention, the
crosslink density of the crosslinkable components, i.e., the degree
of crosslinking, ranges from 5% to 100% of complete crosslinking.
In other embodiments, the crosslink density ranges from 35% to 85%
of full crosslinking. In other embodiments, the crosslink density
ranges from 50% to 85% of full crosslinking. One skilled in the art
will understand that the presence and degree of crosslinking, i.e.,
the crosslink density, can be determined by a variety of methods,
such as dynamic mechanical thermal analysis (DMTA) using a TA
Instruments DMA 2980 DMTA analyzer conducted under nitrogen. This
method determines the glass transition temperature and crosslink
density of free films of coatings or polymers. These physical
properties of a cured material are related to the structure of the
crosslinked network.
[0053] As used herein, a "monovalent hydrocarbon group" means a
monovalent group having a backbone repeat unit based exclusively on
carbon. As used herein, "monovalent" refers to a substituent group
that, as a substituent group, forms only one single, covalent bond.
For example, a monovalent group on the at least one polysiloxane
will form one single covalent bond to a silicon atom in the
backbone of the at least one polysiloxane polymer. As used herein,
"hydrocarbon groups" are intended to encompass both branched and
unbranched hydrocarbon groups.
[0054] Thus, when referring to a "monovalent hydrocarbon group,"
the hydrocarbon group can be branched or unbranched, acyclic or
cyclic, saturated or unsaturated, or aromatic, and can contain from
1 to 24 (or in the case of an aromatic group from 3 to 24) carbon
atoms. Nonlimiting examples of such hydrocarbon groups include
alkyl, alkoxy, aryl, alkaryl, and alkoxyaryl groups. Nonlimiting
examples of lower alkyl groups include, for example, methyl, ethyl,
propyl, and butyl groups. As used herein, "lower alkyl" refers to
alkyl groups having from 1 to 6 carbon atoms. One or more of the
hydrogen atoms of the hydrocarbon can be substituted with
heteroatoms. As used herein, "heteroatoms" means elements other
than carbon, for example, oxygen, nitrogen, and halogen atoms.
[0055] As used herein, "siloxane" means a group comprising a
backbone comprising two or more --SiO-- groups. For example, the
siloxane groups represented by R.sup.1, which is discussed above,
and R, which is discussed below, can be branched or unbranched, and
linear or cyclic. The siloxane groups can be substituted with
pendant organic substituent groups, for example, alkyl, aryl, and
alkaryl groups. The organic substituent groups can be substituted
with heteroatoms, for example, oxygen, nitrogen, and halogen atoms,
reactive functional groups, for example, those reactive functional
groups discussed above with reference to R.sup.2, and mixtures of
any of the foregoing.
[0056] In one embodiment, the present invention is directed to any
composition as previously described, wherein the at least one
polysiloxane (A), which is used to form the polysiloxane borate
ester, comprises at least two reactive functional groups. The at
least one polysiloxane can have a reactive group equivalent weight
ranging from 50 to 1000 mg per gram of the at least one
polysiloxane. In one embodiment, the at least one polysiloxane has
a hydroxyl group equivalent weight ranging from 50 to 1000 mg KOH
per gram of the at least one polysiloxane. In another embodiment,
the at least one polysiloxane has a hydroxyl group equivalent
weight ranging from 100 to 300 mg KOH per gram of the at least one
polysiloxane, while in another embodiment, the hydroxyl group
equivalent weight ranges from 100 to 500 mg KOH per gram.
[0057] In another embodiment, the present invention is directed to
any compositions as described above, wherein R.sup.2 (see
structural unit I above), which may be identical or different,
represents a group comprising at least one reactive functional
group selected from a hydroxyl group, a carboxyl group, an
isocyanate group, a blocked isocyanate group, a primary amine
group, a secondary amine group, an amide group, a carbamate group,
a urea group, a urethane group, a vinyl group, an unsaturated ester
group such as an acrylate group and a methacrylate group, a
maleimide group, a fumarate group, an onium salt group such as a
sulfonium group and an ammonium group, an anhydride group, a
hydroxy alkylamide group, and an epoxy group.
[0058] In another embodiment, the present invention is directed to
any composition as previously described, wherein at least one
R.sup.2 group represents a group comprising at least one reactive
functional group selected from a hydroxyl group and a carbamate
group. In yet another embodiment, the present invention is directed
to any composition as previously described, wherein at least one
R.sup.2 group represents a group comprising at least two reactive
functional groups selected from a hydroxyl group and a carbamate
group. In another embodiment, the present invention is directed to
any composition as previously described, wherein at least one
R.sup.2 group represents a group comprising an oxyalkylene group
and at least two hydroxyl groups.
[0059] In one embodiment, the present invention is directed to any
composition as previously described, wherein the at least one
polysiloxane (A), which is used to form the polysiloxane borate
ester, has the following structure (II) or (III): 2
[0060] wherein: m has a value of at least 1; m' ranges from 0 to
75; n ranges from 0 to 75; n' ranges from 0 to 75; each R, which
may be identical or different, is selected from H, OH, a monovalent
hydrocarbon group, a monovalent siloxane group, and mixtures of any
of the foregoing; and --R.sup.a comprises the following structure
(IV):
--R.sup.3--X (IV)
[0061] wherein --R.sup.3 is selected from an alkylene group, an
oxyalkylene group, an alkylene aryl group, an alkenylene group, an
oxyalkenylene group, and an alkenylene aryl group; and X represents
a group which comprises at least one reactive functional group
selected from a hydroxyl group, a carboxyl group, an isocyanate
group, a blocked isocyanate group, a primary amine group, a
secondary amine group, an amide group, a carbamate group, a urea
group, a urethane group, a vinyl group, an unsaturated ester group
such as an acrylate group and a methacrylate group, a maleimide
group, a fumarate group, an onium salt group such as a sulfonium
group and an ammonium group, an anhydride group, a hydroxy
alkylamide group, and an epoxy group.
[0062] In one embodiment of the present invention, X represents a
group which comprises at least one reactive functional group
selected from a hydroxyl group, a carboxyl group, a primary amine
group, a secondary amine group, an amide group, a carbamate group,
a urea group, an anhydride group, a hydroxy alkylamide group, and
an epoxy group.
[0063] As used herein, "alkylene" refers to an acyclic or cyclic,
saturated hydrocarbon group having a carbon chain length of from C2
to C25. Nonlimiting examples of suitable alkylene groups include,
but are not limited to, those derived from propenyl, 1-butenyl,
1-pentenyl, 1-decenyl, and 1-heneicosenyl, such as, for example
(CH.sub.2).sub.3, (CH.sub.2).sub.4, (CH.sub.2).sub.5,
(CH.sub.2).sub.10, and (CH.sub.2).sub.23, respectively, as well as
isoprene and myrcene.
[0064] As used herein, "oxyalkylene" refers to an alkylene group
containing at least one oxygen atom bonded to, and interposed
between, two carbon atoms and having an alkylene carbon chain
length of from C2 to C25. Nonlimiting examples of suitable
oxyalkylene groups include those derived from trimethylolpropane
monoallyl ether, trimethylolpropane diallyl ether, pentaerythritol
monoallyl ether, polyethoxylated allyl alcohol, and
polypropoxylated allyl alcohol, such as
--(CH.sub.2).sub.3OCH.sub.2C(CH.sub.2OH).sub.2(CH.sub.2CH.sub.2--).
[0065] As used herein, "alkylene aryl" refers to an acyclic
alkylene group substituted with at least one aryl group, for
example, phenyl, and having an alkylene carbon chain length of C2
to C25. The aryl group can be further substituted, if desired.
Nonlimiting examples of suitable substituent groups for the aryl
group include, but are not limited to, hydroxyl groups, benzyl
groups, carboxylic acid groups, and aliphatic hydrocarbon groups.
Nonlimiting examples of suitable alkylene aryl groups include, but
are not limited to, those derived from styrene and
3-isopropenyl-.varies., .varies.-dimethylbenzyl isocyanate, such as
--(CH.sub.2).sub.2C.sub.6H.sub.4-- and
--CH.sub.2CH(CH.sub.3)C.sub.6H.sub- .3(C(CH.sub.3).sub.2(NCO). As
used herein, "alkenylene" refers to an acyclic or cyclic
hydrocarbon group having one or more double bonds and having an
alkenylene carbon chain length of C2 to C25. Nonlimiting examples
of suitable alkenylene groups include those derived from propargyl
alcohol and acetylenic diols, for example,
2,4,7,9-tetramethyl-5-decyne-4,7-diol which is commercially
available from Air Products and Chemicals, Inc. of Allentown, Pa.
as SURFYNOL 104.
[0066] Formulae (II) and (III) are diagrammatic, and are not
intended to imply that the parenthetical portions are necessarily
blocks, although blocks may be used where desired. In some cases
the polysiloxane may comprise a variety of siloxane units. This is
increasingly true as the number of siloxane units employed
increases and especially true when mixtures of a number of
different siloxane units are used. In those instances where a
plurality of siloxane units are used and it is desired to form
blocks, oligomers can be formed which can be joined to form the
block compound. By judicious choice of reactants, compounds having
an alternating structure or blocks of alternating structure may be
used.
[0067] In one embodiment of the present invention the substituent
group R.sup.3 represents an oxyalkylene group. In another
embodiment, R.sup.3 represents an oxyalkylene group, and X
represents a group which comprises at least two reactive functional
groups.
[0068] In another embodiment of the present invention where the at
least one polysiloxane (A) has the structure (II) or (III)
described above, (n+m) ranges from 2 to 9. In yet another
embodiment where the at least one polysiloxane have the structure
(II) or (III) described above, (n+m) ranges from 2 to 3. In another
embodiment, where the at least one polysiloxane have the structure
(II) or (III) described above, (n'+m') ranges from 2 to 9. In
another embodiment where the at least one polysiloxane has the
structure (II) or (III) described above, (n'+m') ranges from 2 to
3.
[0069] In yet another embodiment of the present invention, the
substituent X represents a group comprising at least one reactive
functional group selected from a hydroxyl group and a carbamate
group. In another embodiment, the substituent X represents a group
which comprises at least two hydroxyl groups. In yet another
embodiment, X represents a group which comprises at least one group
selected from H, a monohydroxy-substituted organic group, and a
group having the following structure (V):
R.sup.4--(--CH.sub.2--OH).sub.p (V)
[0070] wherein the substituent group R.sup.4 represents
--CH.sub.2--C--R.sup.3
[0071] when p is 2 and the substituent group R.sup.3 represents a
C.sub.1 to C.sub.4 alkylene group, or the substituent group R.sup.4
represents --CH.sub.2--C -- when p is 3, wherein at least a portion
of X represents a group having the structure (V).
[0072] In another embodiment, where the polysiloxane (A) has the
structure (I) or (11) described above, m is 2 and p is 2.
[0073] In another embodiment of the present invention, the
polysiloxane (A) is formed from at least the following reactants:
(i) at least one polysiloxane of the formula (VI): 3
[0074] wherein each substituent group R, which may be identical or
different, represents a group selected from H, OH, a monovalent
hydrocarbon group, a monovalent siloxane group, and mixtures of any
of the foregoing; at least one of the groups represented by R is H,
and n' ranges from 0 to 100, also can range from 0 to 10, and can
further range from 0 to 5, such that the percent of SiH content of
the polysiloxane ranges from 2 to 50 percent, and can range from 5
to 25 percent; and (ii) at least one molecule which comprises at
least functional group selected from a hydroxyl group, a carboxyl
group, an isocyanate group, a blocked isocyanate group, a primary
amine group, a secondary amine group, an amide group, a carbamate
group, a urea group, a urethane group, a vinyl group, an
unsaturated ester group such as an acrylate group and a
methacrylate group, a maleimide group, a fumarate group, an onium
salt group such as a sulfonium group and an ammonium group, an
anhydride group, a hydroxy alkylamide group, and an epoxy group and
at least one unsaturated bond capable of undergoing a
hydrosilylation reaction. In another embodiment, the at least one
functional group comprises hydroxyl groups.
[0075] It should be appreciated that the various R groups can be
the same or different, and, in certain embodiments, the R groups
will be entirely monovalent hydrocarbon groups or will be a mixture
of different groups such as, for example, monovalent hydrocarbon
groups and hydroxyl groups.
[0076] In another embodiment, this reaction product is ungelled. As
used herein, "ungelled" refers to a reaction product that is
substantially free of crosslinking and has an intrinsic viscosity
when dissolved in a suitable solvent, as determined, for example,
in accordance with ASTM-D1795 or ASTM-D4243. The intrinsic
viscosity of the reaction product is an indication of its molecular
weight. A gelled reaction product, on the other hand, since it is
of an extremely high molecular weight, will have an intrinsic
viscosity too high to measure. As used herein, a reaction product
that is "substantially free of crosslinking" refers to a reaction
product that has a weight average molecular weight (Mw), as
determined by gel permeation chromatography, of less than
1,000,000.
[0077] It also should be noted that the level of unsaturation
contained in reactant (ii) above, can be selected to obtain an
ungelled reaction product. In other words, when a polysiloxane
containing silicon hydride (i) having a higher average value of
Si-H functionality is used, reactant (ii) can have a lower level of
unsaturation. For example, the polysiloxane containing silicon
hydride (i) can be a low molecular weight material where n' ranges
from 0 to 5 and the average value of Si-H functionality is two or
less. In this case, reactant (ii) can contain two or more
unsaturated bonds capable of undergoing hydrosilylation reaction
without the occurrence of gelation.
[0078] Nonlimiting examples of polysiloxanes containing silicon
hydride (i) include 1,1,3,3-tetramethyl disiloxane where n' is 0
and the average Si--H functionality is two; and polymethyl
polysiloxane containing silicon hydride, where n' ranges from 4 to
5 and the average Si-H functionality is approximately two, such as
is commercially available from BASF Corporation as MASILWAX
BASE.RTM..
[0079] Materials for use as reactant (ii) above can include
hydroxyl functional group-containing allyl ethers such as those
selected from trimethylolpropane monoallyl ether, pentaerythritol
monoallyl ether, trimethylolpropane diallyl ether, polyoxyalkylene
alcohols such as polyethoxylated alcohol, polypropoxylated alcohol,
and polybutoxylated alcohol, undecylenic acid-epoxy adducts, allyl
glycidyl ether-carboxylic acid adducts, and mixtures of any of the
foregoing. Mixtures of hydroxyl functional polyallyl ethers with
hydroxyl functional monoallyl ethers or allyl alcohols are suitable
as well. In certain instances, reactant (ii) can contain at least
one unsaturated bond in a terminal position. Reaction conditions
and the ratio of reactants (i) and (ii) are selected so as to form
the desired functional group.
[0080] The hydroxyl functional group-containing polysiloxane (A)
can be prepared by reacting a polysiloxane containing hydroxyl
functional groups with an anhydride to form the half-ester acid
group under reaction conditions that favor only the reaction of the
an hydride and the hydroxyl functional groups, and avoid further
esterification from occurring. Nonlimiting examples of suitable
anhydrides include hexahydrophthalic anhydride, methyl
hexahydrophthalic anhydride, phthalic anhydride, trimellitic
anhydride, succinic anhydride, chlorendic anhydride, alkenyl
succinic anhydride, and substituted alkenyl anhydrides such as
octenyl succinic anhydride, and mixtures of any of the
foregoing.
[0081] The half-ester group-containing reaction product thus
prepared can be further reacted with a monoepoxide to form a
polysiloxane containing secondary hydroxyl group(s). Nonlimiting
examples of suitable monoepoxides are phenyl glycidyl ether,
n-butyl glycidyl ether, cresyl glycidyl ether, isopropyl glycidyl
ether, glycidyl versatate, for example, CARDURA E available from
Shell Chemical Co., and mixtures of any of the foregoing.
[0082] In another embodiment of the present invention, the at least
one polysiloxane (A) is a carbamate functional group-containing
polysiloxane which comprises the reaction product of at least the
following reactants:
[0083] (i) at least one polysiloxane containing silicon hydride of
structure (VI) above where R and n' are as described above for that
structure;
[0084] (ii) at least one hydroxyl functional group-containing
material having one or more unsaturated bonds capable of undergoing
hydrosilylation reaction as described above; and
[0085] (iii) at least one low molecular weight carbamate functional
material, comprising the reaction product of an alcohol or glycol
ether and a urea.
[0086] Examples of such "low molecular weight carbamate functional
material" include, but are not limited to, alkyl carbamate and
hexyl carbamates, and glycol ether carbamates described in U.S.
Pat. Nos. 5,922,475 and 5,976,701, which is incorporated herein by
reference.
[0087] The carbamate functional groups can be incorporated into the
polysiloxane by reacting the hydroxyl functional group-containing
polysiloxane with the low molecular weight carbamate functional
material via a "transcarbamoylation" process. The low molecular
weight carbamate functional material, which can be derived from an
alcohol or glycol ether, can react with free hydroxyl groups of a
polysiloxane polyol, that is, material having an average of two or
more hydroxyl groups per molecule, yielding a carbamate functional
polysiloxane (A) and the original alcohol or glycol ether. Reaction
conditions and the ratio of reactants (i), (ii) and (iii) are
selected so as to form the desired groups.
[0088] The low molecular weight carbamate functional material can
be prepared by reacting the alcohol or glycol ether with urea in
the presence of a catalyst such as butyl stannoic acid. Nonlimiting
examples of suitable alcohols include lower molecular weight
aliphatic, cycloaliphatic and aromatic alcohols, for example,
methanol, ethanol, propanol, butanol, cyclohexanol, 2-ethylhexanol,
and 3-methylbutanol. Nonlimiting examples of suitable glycol ethers
include ethylene glycol methyl ether, and propylene glycol methyl
ether. The incorporation of carbamate functional groups into the
polysiloxane also can be achieved by reacting isocyanic acid with
free hydroxyl groups of the polysiloxane.
[0089] As aforementioned, in addition to or in lieu of hydroxyl or
carbamate functional groups, the at least one polysiloxane (A) can
contain one or more other reactive functional groups such as
carboxyl groups, isocyanate groups, blocked isocyanate groups,
carboxylate groups, primary or secondary amine groups, amide
groups, urea groups, urethane groups, an anhydride group, a hydroxy
alkylamide group, epoxy groups, and mixtures of any of the
foregoing.
[0090] When the at least one polysiloxane (A) contains carboxyl
functional groups, the at least one polysiloxane (A) can be
prepared by reacting at least one polysiloxane containing hydroxyl
functional groups as described above with a polycarboxylic acid or
anhydride. Nonlimiting examples of polycarboxylic acids suitable
for use include adipic acid, succinic acid, and dodecanedioic acid.
Nonlimiting examples of suitable anhydrides include those described
above. Reaction conditions and the ratio of reactants are selected
so as to form the desired functional groups.
[0091] In the case where at least one polysiloxane (A) contains one
or more isocyanate functional groups, the at least one polysiloxane
can be prepared by reacting at least one polysiloxane containing
hydroxyl functional groups, as described above, with a
polyisocyanate, such as a diisocyanate. Nonlimiting examples of
suitable polyisocyanates include aliphatic polyisocyanates, such
as, for example, aliphatic diisocyanates, for example,
1,4-tetramethylene diisocyanate and 1,6-hexamethylene diisocyanate;
cycloaliphatic polyisocyanates, for example, 1,4-cyclohexyl
diisocyanate, isophorone diisocyanate, and .alpha.,.alpha.-xylylene
diisocyanate; and aromatic polyisocyanates, for example,
4,4'-diphenylmethane diisocyanate, 1,3-phenylene diisocyanate, and
tolylene diisocyanate. These and other suitable polyisocyanates are
described in more detail in U.S. Pat. No. 4,046,729, at column 5,
line 26 to column 6, line 28, incorporated herein by reference.
Reaction conditions and the ratio of reactants are selected so as
to form the desired functional groups. The substituent X in
structure (IV) can comprise an oligomeric or polymeric urethane or
urea-containing material which is terminated with isocyanate,
hydroxyl, primary or secondary amine functional groups, or mixtures
of any of the foregoing. When the substituent X comprises such
functional groups, the at least one polysiloxane can be the
reaction product of at least one polysiloxane polyol as described
above, one or more polyisocyanates and, optionally, one or more
compounds having at least two active hydrogen atoms per molecule
selected from hydroxyl groups, primary amine groups, and secondary
amine groups.
[0092] Nonlimiting examples of suitable polyisocyanates are those
described above. Nonlimiting examples of compounds having at least
two active hydrogen atoms per molecule include polyols and
polyamines containing primary or secondary amine groups.
[0093] Nonlimiting examples of suitable polyols include
polyalkylene ether polyols, including thio ethers; polyester
polyols, including polyhydroxy polyesteramides; and
hydroxyl-containing polycaprolactones and hydroxy-containing
acrylic interpolymers. Also useful are polyether polyols formed
from the oxyalkylation of various polyols, for example, glycols
such as ethylene glycol, 1,6-hexanediol, Bisphenol A, and the like,
or higher polyols such as trimethylolpropane, pentaerythritol and
the like. Polyester polyols also can be used. These and other
suitable polyols are described in U.S. Pat. No. 4,046,729 at column
7, line 52 to column 8, line 9; column 8, line 29 to column 9, line
66; and U.S. Pat. No. 3,919,315 at column 2, line 64 to column 3,
line 33, both incorporated herein by reference.
[0094] Nonlimiting examples of suitable polyamines include primary
or secondary diamines or polyamines in which the groups attached to
the nitrogen atoms can be saturated or unsaturated, aliphatic,
alicyclic, aromatic, aromatic-substituted-aliphatic,
aliphatic-substituted-aromatic and heterocyclic. Exemplary suitable
aliphatic and alicyclic diamines include 1,2-ethylene diamine, 1
,2-porphylene diamine, 1,8-octane diamine, isophorone diamine,
propane-2,2-cyclohexyl amine, and the like. Suitable aromatic
diamines include phenylene diamines and the toluene diamines, for
example, o-phenylene diamine and p-tolylene diamine. These and
other suitable polyamines are described in detail in U.S. Pat. No.
4,046,729 at column 6, line 61 to column 7, line 26, incorporated
herein by reference.
[0095] In one embodiment, the substituent group X of the structure
(IV) can comprise a polymeric ester-containing group which is
terminated with hydroxyl or carboxylic acid functional groups. When
X is such a group, at least one polysiloxane can be the reaction
product of one or more polysiloxane polyols as described above, one
or more materials comprising at least one carboxylic acid
functional group, and one or more organic polyols. Nonlimiting
suitable examples of materials comprising at least one carboxylic
acid functional group include carboxylic acid group-containing
polymers well-known in the art, for example, carboxylic acid
group-containing acrylic polymers, polyester polymers, and
polyurethane polymers, such as those described in U.S. Pat. No.
4,681,811. Nonlimiting examples of suitable organic polyols include
those described above.
[0096] To form the at least one polysiloxane (A) containing epoxy
groups, at least one polysiloxane containing hydroxyl functional
groups as described above can be further reacted with a
polyepoxide. The polyepoxide can be an aliphatic or cycloaliphatic
polyepoxide or mixtures of any of the foregoing. Nonlimiting
examples of polyepoxides suitable for use include epoxy functional
acrylic copolymers prepared from at least one ethylenically
unsaturated monomer comprising at least one epoxy group, for
example glycidyl (meth)acrylate and allyl glycidyl ether, and one
or more ethylenically unsaturated monomers which have no epoxy
functionality. The preparation of such epoxy functional acrylic
copolymers is described in detail in U.S. Pat. No. 4,681,811 at
column 4, line 52 to column 5, line 50, incorporated herein by
reference. Reaction conditions and the ratio of reactants are
selected so as to form the desired functional groups.
[0097] In the embodiment of the present invention where the
boron-containing compound (c) is formed from the at least one
functional group-containing polysiloxane (A) and the
boron-containing compound (B), the at least one polysiloxane (A)
can be reacted with the boron-containing compound (B) under
condensation reaction conditions well known in the art. For
example, mixing boric acid or a boric acid equivalent with a polyol
and removing water by distillation either directly or in
combination with a solvent. Other methods for preparing boric acid
esters can be found in "Kirk-Othmer Encyclopedia of Chemical
Technology" 4th edition, Vol 4, p 416; John Wiley and sons; 1992
Also, it should be understood, that the boron-containing compound
(c) can be formed in situ. That is, the coating composition can
comprise boric acid and/or a borate ester and an active
hydrogen-containing reactant, such as a polymer or polysiloxane
comprising hydroxyl functional groups, as separate components. The
boron-containing compound (c) can then be formed, for example, by
forming the condensate, i.e., the borate ester, within the
composition at ambient temperature , or as the coating composition
undergoes a curing reaction. When the boron-containing compound is
formed in situ such as described immediately above, the coating
composition can comprise the condensate reaction product (i.e., the
borate ester), as well as the individual reactants used to form the
borate ester, that is the boric acid and/or borate ester and the
active hydrogen-containing reactant, as three separate
ingredients.
[0098] The boron-containing compound (c), when added to the other
components that form the coating composition, can be present in the
coating composition in an amount sufficient to provide an amount of
boron present in the composition of at least 0.001 weight percent,
often at least 0.025 weight percent, usually at least 0.05 weight
percent, and typically at least 0.10 weight percent, based on total
weight of the resin solids present in the composition. Also, the
boron-containing compound (c), when added to the other components
that form the coating composition, can be present in the coating
composition in an amount sufficient to provide an amount of boron
present in the composition of less than 5 weight percent, often
less than 3 weight percent, usually less than 2.5 weight percent,
and typically less than 2 weight percent, based on total weight of
the resin solids present in the composition. The amount of
boron-containing compound (c) is present in the composition in an
amount sufficient to provide an amount of boron present in the
composition that can range between any combination of these values
inclusive of the recited values.
[0099] As previously mentioned, the present invention is directed
to coating compositions comprising, in addition to the
boron-containing compound (c) discussed in detail above, at least
one functional group-containing polysiloxane (a) and at least one
reactant (b) comprising at least one functional group that is
reactive with the functional group(s) of the polysiloxane (a) (and,
if desired, the boron-containing compound (c)).
[0100] The polysiloxane (a) can be any of the polysiloxanes
described above with reference to polysiloxane (A) used to form the
polysiloxane borate ester. In one embodiment of the present
invention, the polysiloxane (a) comprises at least one of the
structural units (1), wherein R.sup.1, R.sup.2, m and n are as
described above for that structural unit. In a further embodiment
of the present invention, the polysiloxane (a) comprises at least
one polysiloxane having the structure (I) or (II), where R,
R.sup.3, R.sup.a, m, m', n, n', and X are as described above for
these structures.
[0101] In one embodiment, the present invention is directed to
coating compositions as previously described wherein the at least
one polysiloxane (a), when added to the other components that form
the composition, is present in the composition such that the
polysiloxane (a) is present in an amount ranging from 0.01 to 90
weight percent based on total weight of resin solids present in the
composition. In another embodiment, the present invention is
directed to coating compositions as previously described wherein
the at least one polysiloxane (a), when added to the other
components that form the composition, is present in the composition
in an amount such that the polysiloxane (a) is present in the
composition in an amount from at least 2 weight percent based on
total weight of resin solids present in the composition.
[0102] In another embodiment, the present invention is directed to
coating compositions as previously described wherein the at least
one polysiloxane (a), when added to the other components that form
the composition, is present in the composition in an amount such
that the polysiloxane (a) is present in an amount from at least 5
weight percent based on total weight of resin solids present in the
composition. In yet another embodiment, the present invention is
directed to coating compositions as previously described wherein
the at least one polysiloxane (a), when added to the other
components that form the composition, is present in the composition
such that the polysiloxane (a) is present in the composition in an
amount from at least 10 weight percent based on total weight of
resin solids present in the composition.
[0103] In one embodiment, the present invention is directed to
coating compositions as previously described wherein the at least
one polysiloxane (a), when added to the other components that form
the composition, is present in the composition in an amount such
that the amount of the polysiloxane (a) present in the composition
is less than 90 weight percent based on total weight of resin
solids present in the composition. In another embodiment, the
present invention is directed to coating compositions as previously
described wherein the at least one polysiloxane (a), when added to
the other components that form the composition, is present in the
composition in an amount such that the amount of the polysiloxane
(a) present in the composition is less than 80 weight percent based
on total weight of resin solids present in the composition.
[0104] In another embodiment, the present invention is directed to
coating compositions as previously described wherein the at least
one polysiloxane (a), when added to the other components that form
the composition, is present in the composition in an amount such
that the amount of the polysiloxane (a) present in the composition
is less than 65 weight percent based on total weight of resin
solids present in the composition. In yet another embodiment, the
present invention is directed to coating compositions as previously
described wherein the at least one polysiloxane (a), when added to
the other components that form the composition, is present in the
composition in an amount such that the amount of the polysiloxane
(a) is less than 30 weight percent based on total weight of resin
solids present in the composition.
[0105] As used herein "based on total weight of the resin solids"
of the composition means that the amount of the component added
during the formation of the composition is based upon the total
weight of the resin solids (non-volatiles) of the polysiloxane (a),
any film-forming component and any curing agent present during the
formation of the coating composition, but not including the
particles, any solvent, or any additive solids such as hindered
amine stabilizers, UV light absorbers, catalysts, pigments
including pigment extenders and fillers, and flow modifiers.
[0106] As aforementioned, in addition to the components (a) and (c)
described in detail above, the components from which the coating
composition of the present invention is formed can further comprise
(b) at least one reactant comprising at least one functional group
that is reactive with at least one functional group of the at least
one polysiloxane (a), wherein each component is different. As used
herein, the "at least one reactant" refers to any material
comprising a functional group that is reactive with at least one
functional group selected from at least one functional group of the
at least one polysiloxane (a) and, optionally, the at least one
functional group-containing film-forming polymer discussed in
detail below. If applicable the at least one reactant (b) may also
be reactive with the reactive functional groups, if any, comprising
the boron-containing compound (c) discussed above.
[0107] In one embodiment, the at least one reactant (b) is selected
from at least one curing agent. Dependent upon the reactive
functional groups of component (a)(and/or component (c) if
desired), this curing agent can be selected from an aminoplast
resin, a polyisocyanate, a blocked isocyanate compound, a
polyepoxide, a polyacid, an anhydride, an amine, a polyol, and
mixtures of any of the foregoing. In one embodiment, the at least
one reactant (b) is selected from an aminoplast resin and a
polyisocyanate.
[0108] In another embodiment, the present invention is directed to
any composition as previously described wherein the curing agent is
an aminoplast. Aminoplast resins, which comprise phenoplasts, as
curing agents for hydroxyl, carboxylic acid, and carbamate
functional group-containing materials are well known in the art.
Suitable aminoplasts, such as, for example, those discussed above,
are known to those of ordinary skill in the art. Aminoplasts can be
obtained from the condensation reaction of formaldehyde with an
amine or amide. Nonlimiting examples of amines or amides include
melamine, urea, or benzoguanamine. Condensates with other amines or
amides can be used; for example, aldehyde condensates of
glycoluril, which give a high melting crystalline product useful in
powder coatings. While the aldehyde used is most often
formaldehyde, other aldehydes such as acetaldehyde, crotonaldehyde,
and benzaldehyde can be used.
[0109] The aminoplast contains imino and methylol groups and in
certain instances at least a portion of the methylol groups are
etherified with an alcohol to modify the cure response. Any
monohydric alcohol can be employed for this purpose including
methanol, ethanol, n-butyl alcohol, isobutanol, and hexanol.
[0110] Nonlimiting examples of aminoplasts include melamine-,
urea-, or benzoguanamine-formaldehyde condensates, in certain
instances monomeric and at least partially etherified with one or
more alcohols containing from one to four carbon atoms. Nonlimiting
examples of suitable aminoplast resins are commercially available,
for example, from Cytec Industries, Inc. under the trademark
CYMEL.RTM. and from Solutia, Inc. under the trademark
RESIMENE.RTM..
[0111] In another embodiment, the present invention is directed to
coating compositions as previously described wherein the curing
agent comprises an aminoplast resin which, when added to the other
components that form the composition, is generally present in an
amount ranging from 2 weight percent to 65 weight percent, can be
present in an amount ranging from 5 weight percent to 50 weight
percent, and typically is present in an amount ranging from 5
weight percent to 40 weight percent based on total weight of resin
solids present in the composition.
[0112] In yet another embodiment, the present invention is directed
to coating compositions as previously described wherein the at
least one reactant (b) comprises a polyisocyanate curing agent. As
used herein, unless otherwise indicated, the term "polyisocyanate"
is intended to include blocked (or capped) polyisocyanates as well
as unblocked isocyanates. The polyisocyanate can be an aliphatic or
an aromatic polyisocyanate, or a mixture of the foregoing two.
Diisocyanates can be used, although higher polyisocyanates such as
isocyanurates of diisocyanates are often used. Higher
polyisocyanates also can be used in combination with diisocyanates.
Isocyanate prepolymers, for example, reaction products of
polyisocyanates with polyols also can be used. Mixtures of
polyisocyanate curing agents can be used.
[0113] If the polyisocyanate is blocked or capped, any suitable
aliphatic, cycloaliphatic, or aromatic alkyl monoalcohol known to
those skilled in the art can be used as a capping agent for the
polyisocyanate. Other suitable capping agents include oximes and
lactams. When used, the polyisocyanate curing agent is typically
present, when added to the other components which form the coating
composition, in an amount ranging from 5 to 65 weight percent, can
be present in an amount ranging from 10 to 45 weight percent, and
often are present in an amount ranging from 15 to 40 percent by
weight based on the total weight of resin solids present in the
composition.
[0114] Other useful curing agents comprise blocked isocyanate
compounds such as, for example, the tricarbamoyl triazine compounds
described in detail in U.S. Pat. No. 5,084,541, which is
incorporated by reference herein. When used, the blocked
polyisocyante curing agent can be present, when added to the other
components in the composition, in an amount ranging up to 20 weight
percent, and can be present in an amount ranging from 1 to 20
weight percent, based on the total weight of resin solids present
in the composition.
[0115] In one embodiment, the present invention is directed to
film-forming compositions as previously described, wherein the at
least one reactant (b) comprises as a curing agent both an
aminoplast resin and a polyisocyanate.
[0116] Anhydrides as curing agents for hydroxyl functional
group-containing materials also are well known in the art and can
be used in the present invention. Nonlimiting examples of
anhydrides suitable for use as curing agents in the compositions of
the invention include those having at least two carboxylic acid
anhydride groups per molecule which are derived from a mixture of
monomers comprising an ethylenically unsaturated carboxylic acid
anhydride and at least one vinyl co-monomer, for example, styrene,
alpha-methyl styrene, vinyl toluene, and the like. Nonlimiting
examples of suitable ethylenically unsaturated carboxylic acid an
hydrides include maleic anhydride, citraconic anhydride, and
itaconic anhydride. Alternatively, the anhydride can be an
anhydride adduct of a diene polymer such as maleinized
polybutadiene or a maleinized copolymer of butadiene, for example,
a butadiene/styrene copolymer. These and other suitable anhydride
curing agents are described in U.S. Pat. No. 4,798,746 at column
10, lines 16-50; and in U.S. Pat. No. 4,732,790 at column 3, lines
41-57, both of which are incorporated herein by reference.
[0117] Polyepoxides as curing agents for carboxylic acid functional
group-containing materials are well known in the art. Nonlimiting
examples of polyepoxides suitable for use in the compositions of
the present invention comprise polyglycidyl esters (such as
acrylics from glycidyl methacrylate), polyglycidyl ethers of
polyhydric phenols and of aliphatic alcohols, which can be prepared
by etherification of the polyhydric phenol, or aliphatic alcohol
with an epihalohydrin such as epichlorohydrin in the presence of
alkali. These and other suitable polyepoxides are described in U.S.
Pat. No. 4,681,811 at column 5, lines 33 to 58, which is
incorporated herein by reference.
[0118] Suitable curing agents for epoxy functional group-containing
materials comprise polyacid curing agents, such as the acid
group-containing acrylic polymers prepared from an ethylenically
unsaturated monomer containing at least one carboxylic acid group
and at least one ethylenically unsaturated monomer which is free
from carboxylic acid groups. Such acid functional acrylic polymers
can have an acid number ranging from 30 to 150. Acid functional
group-containing polyesters can be used as well. The
above-described polyacid curing agents are described in further
detail in U.S. Pat. No. 4,681,811 at column 6, line 45 to column 9,
line 54, which is incorporated herein by reference.
[0119] Also well known in the art as curing agents for isocyanate
functional group-containing materials are polyols, that is,
materials having two or more hydroxyl groups per molecule,
different from component (b) when component (b) is a polyol.
Nonlimiting examples of such materials suitable for use in the
compositions of the invention include polyalkylene ether polyols,
including thio ethers; polyester polyols, including polyhydroxy
polyesteramides; and hydroxyl-containing polycaprolactones and
hydroxy-containing acrylic copolymers. Also useful are polyether
polyols formed from the oxyalkylation of various polyols, for
example, glycols such as ethylene glycol, 1,6-hexanediol, Bisphenol
A and the like, or higher polyols such as trimethylolpropane,
pentaerythritol, and the like. Polyester polyols also can be used.
These and other suitable polyol curing agents are described in U.S.
Pat. No. 4,046,729 at column 7, line 52 to column 8, line 9; column
8, line 29 to column 9, line 66; and U.S. Pat. No. 3,919,315 at
column 2, line 64 to column 3, line 33, both of which are
incorporated herein by reference.
[0120] Polyamines also can be used as curing agents for isocyanate
functional group-containing materials. Nonlimiting examples of
suitable polyamine curing agents include primary or secondary
diamines or polyamines in which the radicals attached to the
nitrogen atoms can be saturated or unsaturated, aliphatic,
alicyclic, aromatic, aromatic-substituted-aliphatic,
aliphatic-substituted-aromatic, and heterocyclic. Nonlimiting
examples of suitable aliphatic and alicyclic diamines include
1,2-ethylene diamine, 1,2-porphylene diamine, 1,8-octane diamine,
isophorone diamine, propane-2,2-cyclohexyl amine, and the like.
Nonlimiting examples of suitable aromatic diamines include
phenylene diamines and the toluene diamines, for example,
o-phenylene diamine and p-tolylene diamine. These and other
suitable polyamines described in detail in U.S. Pat. No. 4,046,729
at column 6, line 61 to column 7, line 26, which is incorporated
herein by reference.
[0121] When desired, appropriate mixtures of curing agents may be
used. It should be mentioned that compositions can be formulated as
a one-component composition where a curing agent such as an
aminoplast resin and/or a blocked isocyanate compound such as those
described above is admixed with other composition components. The
one-component composition can be storage stable as formulated.
Alternatively, compositions can be formulated as a two-component
composition where a polyisocyanate curing agent such as those
described above can be added to a pre-formed admixture of the other
composition components just prior to application. The pre-formed
admixture can comprise curing agents such as aminoplast resins
and/or blocked isocyanate compounds such as those described
above.
[0122] In another embodiment in which the coating is cured by
actinic radiation or the combination of actinic radiation and
thermal energy, the components from which the coating composition
are formed further can comprise at least one photoinitiator or
photosensitizer which provides free radicals or cations to initiate
the polymerization process. Useful photoinitiators have an
adsorption in the range of 150 to 2,000 nm. Non-limiting examples
of useful photoinitiators include benzoin, benzophenone, hydroxy
benzophenone, anthraquinone, thioxanthone, substituted benzoins
such as butyl isomers of benzoin ethers,
.alpha.,.alpha.-diethoxyacetophenone,.alpha.,.alpha.-dimethoxy-.alpha.-ph-
enylacetophenone, 2-hydroxy-2-methyl-1-phenyl propane 1-one and
2,4,6-trimethyl benzoyl diphenyl phosphine oxide.
[0123] In a further embodiment, the present invention is directed
to coating compositions as previously described which further
comprise at least one reactive functional group-containing, film
forming polymer. This film forming polymer can be different from
and in addition to the at least one polysiloxane (a), the at least
one reactant (b), and the boron-containing compound (c). This
film-forming polymer can have at least one functional group
reactive with at least one functional group selected from the at
least one reactive functional group of the at least one
polysiloxane (a), the at least one functional group of the reactant
(b), and, if desired, the boron-containing compound (c). In one
embodiment, this at least one additional polymer can be selected
from at least one of polyether polymers, polyester polymers,
acrylic polymers, silicon-based polymers, and polyurethane
polymers.
[0124] In a particular embodiment of the present invention, the
film-forming polymer can comprise at least one reactive functional
group selected from a hydroxyl group, a carboxyl group, an
isocyanate group, a blocked isocyanate group, a primary amine
group, a secondary amine group, an amide group, a carbamate group,
a urea group, a urethane group, a vinyl group, an unsaturated ester
group, a maleimide group, a fumarate group, an anhydride group, a
hydroxy alkylamide group, and an epoxy group.
[0125] In another embodiment of the present invention, the
film-forming polymer comprises at least one reactive functional
group selected from a hydroxyl group, a carbamate group, an epoxy
group, an isocyanate group, and a carboxyl group. In another
embodiment, the polymer comprises at least one reactive functional
group selected from a hydroxyl group, and a carbamate group.
[0126] The film-forming polymer can comprise a mixture of any of
the foregoing reactive functional groups.
[0127] Suitable film-forming polymers suitable for use as the at
least one reactive functional group-containing film-forming polymer
can include any of a variety of functional polymers known in the
art. For example, suitable hydroxyl group-containing polymers can
include acrylic polyols, polyester polyols, polyurethane polyols,
polyether polyols, and mixtures thereof. In a particular embodiment
of the present invention, the film-forming polymer is an acrylic
polyol having a hydroxyl equivalent weight ranging from 1000 to 100
grams per solid equivalent, preferably 500 to 150 grams per solid
equivalent.
[0128] Suitable hydroxyl group and/or carboxyl group-containing
acrylic polymers can be prepared from polymerizable ethylenically
unsaturated monomers and are typically copolymers of (meth)acrylic
acid and/or hydroxylalkyl esters of (meth)acrylic acid with one or
more other polymerizable ethylenically unsaturated monomers such as
alkyl esters of (meth)acrylic acid including methyl (meth)acrylate,
ethyl (meth)acrylate, butyl (meth)acrylate and 2-ethyl
hexylacrylate, and vinyl aromatic compounds such as styrene,
alpha-methyl styrene, and vinyl toluene. As used herein,
"(meth)acrylate" and like terms is intended to include both
acrylates and methacrylates.
[0129] In a one embodiment of the present invention the acrylic
polymer can be prepared from ethylenically unsaturated,
beta-hydroxy ester functional monomers. Such monomers can be
derived from the reaction of an ethylenically unsaturated acid
functional monomer, such as monocarboxylic acids, for example,
acrylic acid, and an epoxy compound which does not participate in
the free radical initiated polymerization with the unsaturated acid
monomer. Examples of such epoxy compounds include glycidyl ethers
and esters. Suitable glycidyl ethers include glycidyl ethers of
alcohols and phenols such as butyl glycidyl ether, octyl glycidyl
ether, phenyl glycidyl ether and the like. Suitable glycidyl esters
include those which are commercially available from Shell Chemical
Company under the tradename CARDURA E; and from Exxon Chemical
Company under the tradename GLYDEXX-10. Alternatively, the
beta-hydroxy ester functional monomers can be prepared from an
ethylenically unsaturated, epoxy functional monomer, for example
glycidyl (meth)acrylate and allyl glycidyl ether, and a saturated
carboxylic acid, such as a saturated monocarboxylic acid, for
example isostearic acid.
[0130] Epoxy functional groups can be incorporated into the polymer
prepared from polymerizable ethylenically unsaturated monomers by
copolymerizing oxirane group-containing monomers, for example
glycidyl (meth)acrylate and allyl glycidyl ether, with other
polymerizable ethylenically unsaturated monomers, such as those
discussed above. Preparation of such epoxy functional acrylic
polymers is described in detail in U.S. Pat. No. 4,001,156 at
columns 3 to 6, incorporated herein by reference.
[0131] Carbamate functional groups can be incorporated into the
polymer prepared from polymerizable ethylenically unsaturated
monomers by copolymerizing, for example, the above-described
ethylenically unsaturated monomers with a carbamate functional
vinyl monomer such as a carbamate functional alkyl ester of
methacrylic acid. Useful carbamate functional alkyl esters can be
prepared by reacting, for example, a hydroxyalkyl carbamate, such
as the reaction product of ammonia and ethylene carbonate or
propylene carbonate, with methacrylic anhydride. Other useful
carbamate functional vinyl monomers include, for instance, the
reaction product of hydroxyethyl methacrylate, isophorone
diisocyanate, and hydroxypropyl carbamate; or the reaction product
of hydroxypropyl methacrylate, isophorone diisocyanate, and
methanol. Still other carbamate functional vinyl monomers may be
used, such as the reaction product of isocyanic acid (HNCO) with a
hydroxyl functional acrylic or methacrylic monomer such as
hydroxyethyl acrylate, and those described in U.S. Pat. No.
3,479,328, incorporated herein by reference. Carbamate functional
groups can also be incorporated into the acrylic polymer by
reacting a hydroxyl functional acrylic polymer with a low molecular
weight alkyl carbamate such as methyl carbamate. Pendant carbamate
groups can also be incorporated into the acrylic polymer by a
"transcarbamoylation" reaction in which a hydroxyl functional
acrylic polymer is reacted with a low molecular weight carbamate
derived from an alcohol or a glycol ether. The carbamate groups
exchange with the hydroxyl groups yielding the carbamate functional
acrylic polymer and the original alcohol or glycol ether. Also,
hydroxyl functional acrylic polymers can be reacted with isocyanic
acid to provide pendent carbamate groups. Likewise, hydroxyl
functional acrylic polymers can be reacted with urea to provide
pendent carbamate groups.
[0132] The polymers prepared from polymerizable ethylenically
unsaturated monomers can be prepared by solution polymerization
techniques, which are well-known to those skilled in the art, in
the presence of suitable catalysts such as organic peroxides or azo
compounds, for example, benzoyl peroxide or
N,N-azobis(isobutylronitrile). The polymerization can be carried
out in an organic solution in which the monomers are soluble by
techniques conventional in the art. Alternatively, these polymers
can be prepared by aqueous emulsion or dispersion polymerization
techniques which are well-known in the art. The ratio of reactants
and reaction conditions are selected to result in an acrylic
polymer with the desired pendent functionality.
[0133] Polyester polymers are also useful in the coating
compositions of the invention as the film-forming polymer. Useful
polyester polymers typically include the condensation products of
polyhydric alcohols and polycarboxylic acids. Suitable polyhydric
alcohols can include ethylene glycol, neopentyl glycol, trimethylol
propane, and pentaerythritol. Suitable polycarboxylic acids can
include adipic acid, 1,4-cyclohexyl dicarboxylic acid, and
hexahydrophthalic acid. Besides the polycarboxylic acids mentioned
above, functional equivalents of the acids such as anhydrides where
they exist or lower alkyl esters of the acids such as the methyl
esters can be used. Also, small amounts of monocarboxylic acids
such as stearic acid can be used. The ratio of reactants and
reaction conditions are selected to result in a polyester polymer
with the desired pendent functionality, i.e., carboxyl or hydroxyl
functionality.
[0134] For example, hydroxyl group-containing polyesters can be
prepared by reacting an anhydride of a dicarboxylic acid such as
hexahydrophthalic anhydride with a diol such as neopentyl glycol in
a 1:2 molar ratio. Where it is desired to enhance air-drying,
suitable drying oil fatty acids may be used and include those
derived from linseed oil, soya bean oil, tall oil, dehydrated
castor oil, or tung oil.
[0135] Carbamate functional polyesters can be prepared by first
forming a hydroxyalkyl carbamate that can be reacted with the
polyacids and polyols used in forming the polyester. Alternatively,
terminal carbamate functional groups can be incorporated into the
polyester by reacting isocyanic acid with a hydroxy functional
polyester. Also, carbamate functionality can be incorporated into
the polyester by reacting a hydroxyl polyester with a urea.
Additionally, carbamate groups can be incorporated into the
polyester by a transcarbamoylation reaction. Preparation of
suitable carbamate functional group-containing polyesters are those
described in U.S. Pat. No. 5,593,733 at column 2, line 40 to column
4, line 9, incorporated herein by reference.
[0136] Polyurethane polymers containing terminal isocyanate or
hydroxyl groups also can be used as the polymer (d) in the coating
compositions of the invention. The polyurethane polyols or
NCO-terminated polyurethanes which can be used are those prepared
by reacting polyols including polymeric polyols with
polyisocyanates. Polyureas containing terminal isocyanate or
primary and/or secondary amine groups which also can be used are
those prepared by reacting polyamines including polymeric
polyamines with polyisocyanates. The hydroxyl/isocyanate or
amine/isocyanate equivalent ratio is adjusted and reaction
conditions are selected to obtain the desired terminal groups.
Examples of suitable polyisocyanates include those described in
U.S. Pat. No. 4,046,729 at column 5, line 26 to column 6, line 28,
incorporated herein by reference. Examples of suitable polyols
include those described in U.S. Pat. No. 4,046,729 at column 7,
line 52 to column 10, line 35, incorporated herein by reference.
Examples of suitable polyamines include those described in U.S.
Pat. No. 4,046,729 at column 6, line 61 to column 7, line 32 and in
U.S. Pat. No. 3,799,854 at column 3, lines 13 to 50, both
incorporated herein by reference.
[0137] Carbamate functional groups can be introduced into the
polyurethane polymers by reacting a polyisocyanate with a polyester
having hydroxyl functionality and containing pendent carbamate
groups. Alternatively, the polyurethane can be prepared by reacting
a polyisocyanate with a polyester polyol and a hydroxyalkyl
carbamate or isocyanic acid as separate reactants. Examples of
suitable polyisocyanates are aromatic isocyanates, such as
4,4'-diphenylmethane diisocyanate, 1,3-phenylene diisocyanate and
toluene diisocyanate, and aliphatic polyisocyanates, such as
1,4-tetramethylene diisocyanate and 1,6-hexamethylene diisocyanate.
Cycloaliphatic diisocyanates, such as 1,4-cyclohexyl diisocyanate
and isophorone diisocyanate also can be employed.
[0138] Examples of suitable polyether polyols include polyalkylene
ether polyols such as those having the following structural
formulas (VII) or (VIII): 4
[0139] wherein the substituent R is hydrogen or a lower alkyl group
containing from 1 to 5 carbon atoms including mixed substituents,
and n has a value typically ranging from 2 to 6 and m has a value
ranging from 8 to 100 or higher. Exemplary polyalkylene ether
polyols include poly(oxytetramethylene) glycols,
poly(oxytetraethylene) glycols, poly(oxy-1,2-propylene) glycols,
and poly(oxy-1,2-butylene) glycols.
[0140] Also useful are polyether polyols formed from oxyalkylation
of various polyols, for example, glycols such as ethylene glycol,
1,6-hexanediol, Bisphenol A, and the like, or other higher polyols
such as trimethylolpropane, pentaerythritol, and the like. Polyols
of higher functionality which can be utilized as indicated can be
made, for instance, by oxyalkylation of compounds such as sucrose
or sorbitol. One commonly utilized oxyalkylation method is reaction
of a polyol with an alkylene oxide, for example, propylene or
ethylene oxide, in the presence of an acidic or basic catalyst.
Specific examples of polyethers include those sold under the names
TERATHANE and TERACOL, available from E. I. Du Pont de Nemours and
Company, Inc.
[0141] Generally, the polymers having reactive functional groups
which are useful in the coating compositions of the invention have
a weight average molecular weight (Mw) typically ranging from 1000
to 20,000 preferably 1500 to 15,000 and more preferably 2000 to
12,000 as determined by gel permeation chromatography using a
polystyrene standard.
[0142] It should be mentioned that when both (a) and (d) are
present, the reactive functional groups of (a) and (d) can be the
same or different, but both must be reactive with the functional
groups of the curing agent (b). Examples of such reactive
functional groups include hydroxyl, carboxylic acid, isocyanate,
carboxylate, primary amine, secondary amine, amide, carbamate, and
epoxy functional groups. Hydroxyl and/or carbamate functional
group-containing polymers are preferred.
[0143] The polymer having reactive functional groups, if employed,
can be present in the coating compositions of the invention in an
amount of at least 2percent by weight, usually at least 5 percent
by weight, and typically at least 10 percent by weight based on
weight of total resin solids in the coating composition. Also, the
polymer having reactive functional groups can be present in the
coating compositions of the invention in an amount less than 80
percent by weight, usually less than 60 percent by weight, and
typically less than 50 percent by weight based on weight of total
resin solids in the coating composition. The amount of the polymer
having reactive functional groups present in the coating
compositions of the present invention can range between any
combination of these values inclusive of the recited values.
[0144] The coating compositions of the present invention can be
solvent-based compositions, water-based compositions, in solid
particulate form, that is, a powder composition, in the form of a
powder slurry or an aqueous dispersion. The components of the
present invention used to form the compositions of the present
invention can be dissolved or dispersed in an organic solvent.
Nonlimiting examples of suitable organic solvents include alcohols,
such as butanol; ketones, such as methyl amyl ketone; aromatic
hydrocarbons, such as xylene; and glycol ethers, such as, ethylene
glycol monobutyl ether; esters; other solvents; and mixtures of any
of the foregoing.
[0145] In solvent based compositions, the organic solvent is
generally present in amounts ranging from 5 to 80 percent by weight
based on total weight of the resin solids of the components which
form the composition, and can be present in an amount ranging from
30 to 50 percent by weight. The compositions as described above can
have a total solids content ranging from 40 to 75 percent by weight
based on total weight of the resin solids of the components which
form the composition, and can have a total solids content ranging
from 50 to 70 percent by weight. Alternatively, the inventive
compositions can be in solid particulate form suitable for use as a
powder coating, or suitable for dispersion in a liquid medium such
as water for use as a powder slurry.
[0146] In a further embodiment, the film-forming compositions as
previously described further comprise a catalyst which is present
during the composition's formation. In one embodiment, the catalyst
is present in an amount sufficient to accelerate the reaction
between at least one reactive functional group of the at least one
reactant (b) and/or at least one reactive functional group of the
at least one polysiloxane (a) and/or the boron-containing compound
(c), if appropriate, and/or the functional group-containing
film-forming polymer, if used.
[0147] Nonlimiting examples of suitable catalysts include acidic
materials, for example, acid phosphates, such as phenyl acid
phosphate, and substituted or unsubstituted sulfonic acids such as
dodecylbenzene sulfonic acid or paratoluene sulfonic acid.
Non-limiting examples of suitable catalysts for reactions between
isocyanate groups and active hydrogen-containing materials, for
example, those comprising hydroxyl groups, include tin catalysts
such as dibutyl tin dilaurate and dibutyl tin oxide. Non-limiting
examples of epoxy acid base catalysts include tertiary amines such
as N,N'-dimethyldodecyl amine catalysts. In another embodiment, the
catalyst can be a phosphatized polyester or a phosphatized epoxy.
In this embodiment, the catalyst can be, for example, the reaction
product of phosphoric acid and a bisphenol A diglycidyl ether
having two hydrogenated phenolic rings, such as DRH-151, which is
commercially available from Shell Chemical Co. The catalyst can be
present, when added to the other components that form the
composition, in an amount ranging from 0.1 to 5.0 percent by
weight, and is typically present in an amount ranging from 0.5 to
1.5 percent by weight based on the total weight of resin solids
present in the composition.
[0148] In another embodiment, additional components can be present
during the formation of the compositions as previously described.
These additional components include, but are not limited to,
particles different from components (a), (b) and (c),
flexibilizers, plasticizers, surface active agents, thixotropic
agents, rheology control modifiers, anti-gassing agents, organic
cosolvents, flow controllers, hindered amine light stabilizers,
anti-oxidants, UV light absorbers, coloring agents or tints, and
similar additives conventional in the art, as well as mixtures of
any of the foregoing can be included in the composition. These
additional ingredients can be present, when added to the other
components that form the composition, in an amount up to 40 percent
by weight based on the total weight of resin solids present in the
composition.
[0149] In one embodiment, the present invention is directed to
compositions as previously described wherein the composition
further comprises a plurality of particles. In another embodiment,
the present invention is directed to any composition as previously
described wherein the particles have an average particle size of
less than 100 microns prior to incorporation into the composition.
In another embodiment, the present invention is directed to any
composition as previously described wherein the particles have an
average particle size ranging from 1 to less than 1000 nanometers
prior to incorporation into the composition. In yet another
embodiment, the present invention is directed to any composition as
previously described wherein the particles have an average particle
size ranging from 1 to 100 nanometers prior to incorporation into
the composition.
[0150] In another embodiment, the present invention is directed to
any composition as previously described wherein the particles have
an average particle size ranging from 5 to 50 nanometers prior to
incorporation into the composition. In another embodiment, the
present invention is directed to any composition as previously
described wherein the particles have an average particle size
ranging from 5 to 25 nanometers prior to incorporation into the
composition.
[0151] In an embodiment where the average particle size of the
particles is greater than one micron, the average particle size can
be measured according to known laser scattering techniques. For
example, the average particle size of such particles is measured
using a Horiba Model LA 900 laser diffraction particle size
instrument, which uses a helium-neon laser with a wave length of
633 nm to measure the size of the particles and assumes the
particle has a spherical shape, i.e., the "particle size" refers to
the smallest sphere that will completely enclose the particle.
[0152] In an embodiment of the present invention wherein the size
of the particles is less than or equal to one micron, the average
particle size can be determined by visually examining an electron
micrograph of a transmission electron microscopy ("TEM") image,
measuring the diameter of the particles in the image, and
calculating the average particle size based on the magnification of
the TEM image. One of ordinary skill in the art will understand how
to prepare such a TEM image, and a description of one such method
is disclosed in the examples set forth below. In one nonlimiting
embodiment of the present invention, a TEM image with
105,000.times. magnification is produced, and a conversion factor
is obtained by dividing the magnification by 1000. Upon visual
inspection, the diameter of the particles is measured in
millimeters, and the measurement is converted to nanometers using
the conversion factor. The diameter of the particle refers to the
smallest diameter sphere that will completely enclose the
particle.
[0153] The shape (or morphology) of the particles can vary
depending upon the specific embodiment of the present invention and
its intended application. For example generally spherical
morphologies (such as solid beads, microbeads, or hollow spheres),
can be used, as well as particles that are cubic, platy, or
acicular (elongated or fibrous). Additionally, the particles can
have an internal structure that is hollow, porous or void free, or
a combination of any of the foregoing, e.g., a hollow center with
porous or solid walls. For more information on suitable particle
characteristics see H. Katz et al. (Ed.), Handbook of Fillers and
Plastics (1987) at pages 9-10, which are specifically incorporated
by reference herein.
[0154] It will be recognized by one skilled in the art that
mixtures of one or more particles having different average particle
sizes can be incorporated into the compositions in accordance with
the present invention to impart the desired properties and
characteristics to the compositions. For example, particles of
varying particle sizes can be used in the compositions according to
the present invention.
[0155] The particles can be formed from materials selected from
polymeric and nonpolymeric inorganic materials, polymeric and
nonpolymeric organic materials, composite materials, and mixtures
of any of the foregoing. As used herein, the term "polymeric
inorganic material" means a polymeric material having a backbone
repeat unit based on an element or elements other than carbon. For
more information see James Mark et al., Inorganic Polymers,
Prentice Hall Polymer Science and Engineering Series, (1992) at
page 5, which is specifically incorporated by reference herein. As
used herein, the term "polymeric organic materials" means synthetic
polymeric materials, semisynthetic polymeric materials and natural
polymeric materials, all of which have a backbone repeat unit based
on carbon.
[0156] An "organic material," as used herein, means carbon
containing compounds wherein the carbon is typically bonded to
itself and to hydrogen, and often to other elements as well, and
excludes binary compounds such as the carbon oxides, the carbides,
carbon disulfide, etc.; such ternary compounds as the metallic
cyanides, metallic carbonyls, phosgene, carbonyl sulfide, etc.; and
carbon-containing ionic compounds such as metallic carbonates, for
example, calcium carbonate and sodium carbonate. See R. Lewis, Sr.,
Hawley's Condensed Chemical Dictionary, (12th Ed. 1993) at pages
761-762, and M. Silberberg, Chemistry The Molecular Nature of
Matter and Change (1996) at page 586, which are specifically
incorporated by reference herein.
[0157] As used herein, the term "inorganic material" means any
material that is not an organic material.
[0158] As used herein, the term "composite material" means a
combination of two or more differing materials. The particles
formed from composite materials generally have a hardness at their
surface that is different from the hardness of the internal
portions of the particle beneath its surface. More specifically,
the surface of the particle can be modified in any manner well
known in the art, including, but not limited to, chemically or
physically changing its surface characteristics using techniques
known in the art.
[0159] For example, a particle can be formed from a primary
material that is coated, clad or encapsulated with one or more
secondary materials to form a composite particle that has a softer
surface. In yet another alternative embodiment, particles formed
from composite materials can be formed from a primary material that
is coated, clad or encapsulated with a different form of the
primary material. For more information on particles useful in the
present invention, see G. Wypych, Handbook of Fillers, 2nd Ed.
(1999) at pages 15-202, which are specifically incorporated by
reference herein.
[0160] The particles suitable for use in the compositions of the
invention can comprise inorganic elements or compounds known in the
art. Suitable particles can be formed from ceramic materials,
metallic materials, and mixtures of any of the foregoing. Suitable
ceramic materials comprise metal oxides, metal nitrides, metal
carbides, metal sulfides, metal silicates, metal borides, metal
carbonates, and mixtures of any of the foregoing. Specific,
nonlimiting examples of metal nitrides are, for example, boron
nitride; specific, nonlimiting examples of metal oxides are, for
example, zinc oxide; nonlimiting examples of suitable metal
sulfides are, for example, molybdenum disulfide, tantalum
disulfide, tungsten disulfide, and zinc sulfide; nonlimiting
suitable examples of metal silicates are, for example, aluminum
silicates and magnesium silicates such as vermiculite.
[0161] The particles can comprise, for example, a core of
essentially a single inorganic oxide such as silica in colloidal,
fumed, or amorphous form, alumina or colloidal alumina, titanium
dioxide, cesium oxide, yttrium oxide, colloidal yttria, zirconia,
e.g., colloidal or amorphous zirconia, and mixtures of any of the
foregoing; or an inorganic oxide of one type upon which is
deposited an organic oxide of another type. It should be understood
that when the composition of the invention is employed as a
transparent topcoat, for example, as a clearcoat in a
multi-component composite coating composition, particles should not
seriously interfere with the optical properties of the composition.
As used herein, "transparent" means that the cured coating has a
BYK Haze index of less than 50 as measured using a BYK/Haze Gloss
instrument.
[0162] Nonpolymeric, inorganic materials useful in forming the
particles of the present invention comprise inorganic materials
selected from graphite, metals, oxides, carbides, nitrides,
borides, sulfides, silicates, carbonates, sulfates, and hydroxides.
A nonlimiting example of a useful inorganic oxide is zinc oxide.
Nonlimiting examples of suitable inorganic sulfides include
molybdenum disulfide, tantalum disulfide, tungsten disulfide, and
zinc sulfide. Nonlimiting examples of useful inorganic silicates
include aluminum silicates and magnesium silicates, such as
vermiculite. Nonlimiting examples of suitable metals include
molybdenum, platinum, palladium, nickel, aluminum, copper, gold,
iron, silver, alloys, and mixtures of any of the foregoing.
[0163] In one embodiment, the present invention is directed to any
composition as previously described wherein the particles are
selected from fumed silica, amorphous silica, colloidal silica,
alumina, colloidal alumina, titanium dioxide, cesium oxide, yttrium
oxide, colloidal yttria, zirconia, colloidal zirconia, and mixtures
of any of the foregoing. In another embodiment, the present
invention is directed to any composition as previously described
wherein the particles include colloidal silica. As disclosed above,
these materials can be surface treated or untreated.
[0164] The composition can comprise precursors suitable for forming
silica particles in situ by a sol-gel process. The composition
according to the present invention can comprise alkoxy silanes
which can be hydrolyzed to form silica particles in situ. For
example, tetraethylortho silicate can be hydrolyzed with an acid
such as hydrochloric acid and condensed to form silica particles.
Other useful particles include surface-modified silicas such as are
described in U.S. Pat. No. 5,853,809 at column 6, line 51 to column
8, line 43, which is incorporated herein by reference.
[0165] In one embodiment of the present invention, the particles
have a hardness value greater than the hardness value of materials
that can abrade a polymeric coating or a polymeric substrate.
Examples of materials that can abrade the polymeric coating or
polymeric substrate include, but are not limited to, dirt, sand,
rocks, glass, carwash brushes, and the like. The hardness values of
the particles and the materials that can abrade the polymeric
coating or polymeric substrate can be determined by any
conventional hardness measurement method, such as Vickers or
Brinell hardness, but is preferably determined according to the
original Mohs' hardness scale which indicates the relative scratch
resistance of the surface of a material on a scale of one to ten.
The Mohs' hardness values of several nonlimiting examples of
particles formed from inorganic materials suitable for use in the
present invention are given in Table A below.
1 TABLE A Particle material Mohs` hardness (original scale) Boron
nitride 2.sup.1 Graphite 0.5-1.sup.2 Molybdenum disulfide 1.sup.3
Talc 1-1.5.sup.4 Mica 2.8-3.2.sup.5 Kaolinite 2.0-2.56 Gypsum
1.6-2.sup.7 Calcite (calcium carbonate) 3.sup.8 Calcium fluoride
4.sup.9 zinc oxide 4.5.sup.10 Aluminum 2.5.sup.11 Copper
2.5-3.sup.12 Iron 4-5.sup.13 Gold 2.5-3.sup.14 Nickel 5.sup.15
Palladium 4.8.sup.16 Platinum 4.3.sup.17 Silver 2.5-4.sup.18 Zinc
sulfide 3.5-4.sup.19 .sup.1K. Ludema, Friction, Wear, Lubrication,
(1996) at page 27, which is hereby incorporated by reference.
.sup.2R. Weast (Ed.), Handbook of Chemistry and Physics, CRC Press
(1975) at page F-22. .sup.3R. Lewis, Sr., Hawley's Condensed
Chemical Dictionary, (12th Ed. 1993) at page 793, which is hereby
incorporated by reference. .sup.4Hawley's Condensed Chemical
Dictionary, (12th Ed. 1993) at page 1113, which is hereby
incorporated by reference. .sup.5Hawley's Condensed Chemical
Dictionary, (12th Ed. 1993) at page 784, which is hereby
incorporated by reference. .sup.6Handbook of Chemistry and Physics
at page F-22. .sup.7Handbook of Chemistry and Physics at page F-22.
.sup.8Friction Wear, Lubrication at page 27. .sup.9Friction, Wear,
Lubrication at page 27. .sup.10Friction, Wear, Lubrication at page
27. .sup.11Friction, Wear, Lubrication at page 27. .sup.12Handbook
of Chemistry and Physics at page F-22. .sup.13Handbook of Chemistry
and Physics at page F-22. .sup.14Handbook of Chemistry and Physics
at page F-22. .sup.15Handbook of Chemistry and Physics at page
F-22. .sup.16Handbook of Chemistry and Physics at page F-22.
.sup.17Handbook of Chemistry and Physics at page F-22.
.sup.18Handbook of Chemistry and Physics at page F-22. .sup.19R.
Weast (Ed.), Handbook of Chemistry and Physics, CRC Press
(71.sup.st Ed. 1990) at page 4-158.
[0166] In one embodiment, the Mohs' hardness value of the particles
is greater than 5. In certain embodiments, the Mohs' hardness value
of the particles, such as silica, is greater than 6.
[0167] As mentioned above, the Mohs' hardness scale relates to the
resistance of a material to scratching. The present invention
therefore further contemplates particles that have a hardness at
their surface that is different from the hardness of the internal
portions of the particle beneath its surface. More specifically,
and as discussed above, the surface of the particle can be modified
in any manner well known in the art, including, but not limited to,
chemically changing the particle's surface characteristics using
techniques known in the art such that the surface hardness of the
particle is greater the hardness of the materials that can abrade
the polymeric coating or polymeric substrate while the hardness of
the particle beneath the surface is less than the hardness of the
materials that can abrade the polymeric coating or polymeric
substrate.
[0168] As another alternative, a particle can be formed from a
primary material that is coated, clad or encapsulated with one or
more secondary materials to form a composite material that has a
harder surface. Alternatively, a particle can be formed from a
primary material that is coated, clad or encapsulated with a
differing form of the primary material to form a composite material
that has a harder surface.
[0169] In one example, and without limiting the present invention,
an inorganic particle formed from an inorganic material such as
silicon carbide or aluminum nitride can be provided with a silica,
carbonate or nanoclay coating to form a useful composite particle.
In another nonlimiting example, a silane coupling agent with alkyl
side chains can interact with the surface of an inorganic particle
formed from an inorganic oxide to provide a useful composite
particle having a "softer" surface. Other examples include
cladding, encapsulating or coating particles formed from
nonpolymeric or polymeric materials with differing nonpolymeric or
polymeric materials. A specific nonlimiting example of such
composite particles is DUALITE.TM., which is a synthetic polymeric
particle coated with calcium carbonate that is commercially
available from Pierce and Stevens Corporation of Buffalo, NY.
[0170] In one nonlimiting embodiment of the invention, the
particles are formed from solid lubricant materials. As used
herein, the term "solid lubricant" means any solid used between two
surfaces to provide protection from damage during relative movement
or to reduce friction and wear. In one embodiment, the solid
lubricants are inorganic solid lubricants. As used herein,
"inorganic solid lubricant" means that the solid lubricants have a
characteristic crystalline habit which causes them to shear into
thin, flat plates which readily slide over one another and thus
produce an antifriction lubricating effect. See R. Lewis, Sr.,
Hawley's Condensed Chemical Dictionary, (12th Ed. 1993) at page
712, which is specifically incorporated by reference herein.
Friction is the resistance to sliding one solid over another. F.
Clauss, Solid Lubricants and Self-Lubricating Solids (1972) at page
1, which is specifically incorporated by reference herein.
[0171] In one nonlimiting embodiment of the invention, the
particles have a lamellar structure. Particles having a lamellar
structure are composed of sheets or plates of atoms in hexagonal
array, with strong bonding within the sheet and weak van der Waals
bonding between sheets, providing low shear strength between
sheets. A nonlimiting example of a lamellar structure is a
hexagonal crystal structure. Inorganic solid particles having a
lamellar fullerene (i.e., buckyball) structure also are useful in
the present invention.
[0172] Nonlimiting examples of suitable materials having a lamellar
structure that are useful in forming the particles of the present
invention include boron nitride, graphite, metal dichalcogenides,
mica, talc, gypsum, kaolinite, calcite, cadmium iodide, silver
sulfide, and mixtures of any of the foregoing. Suitable metal
dichalcogenides include molybdenum disulfide, molybdenum
diselenide, tantalum disulfide, tantalum diselenide, tungsten
disulfide, tungsten diselenide, and mixtures of any of the
foregoing.
[0173] The particles can be formed from nonpolymeric, organic
materials. Nonlimiting examples of nonpolymeric, organic materials
useful in the present invention include, but are not limited to,
stearates (such as zinc stearate and aluminum stearate), diamond,
carbon black, and stearamide.
[0174] The particles can be formed from inorganic polymeric
materials. Nonlimiting examples of useful inorganic polymeric
materials include polyphosphazenes, polysilanes, polysiloxane,
polygeremanes, polymeric sulfur, polymeric selenium, silicones, and
mixtures of any of the foregoing. A specific, nonlimiting example
of a particle formed from an inorganic polymeric material suitable
for use in the present invention is TOSPEARL.sup.20, which is a
particle formed from cross-linked siloxanes and is commercially
available from Toshiba Silicones Company, Ltd. of Japan.
[0175] The particles can be formed from synthetic, organic
polymeric materials. Nonlimiting examples of suitable organic
polymeric materials include, but are not limited to, thermoset
materials and thermoplastic materials. As used herein, a
"thermoplastic" material is a material that softens when exposed to
heat and returns to its original condition when cooled to room
temperature. Nonlimiting examples of suitable thermoplastic
materials include thermoplastic polyesters such as polyethylene
terephthalate, polybutylene terephthalate, and polyethylene
naphthalate, polycarbonates, polyolefins such as polyethylene,
polypropylene, and polyisobutene, acrylic polymers such as
copolymers of styrene and an acrylic acid monomer, and polymers
containing methacrylate, polyamides, thermoplastic polyurethanes,
vinyl polymers, and mixtures of any of the foregoing.
[0176] Nonlimiting examples of suitable thermoset materials include
thermoset polyesters, vinyl esters, epoxy materials, phenolics,
aminoplasts, thermoset polyurethanes, and mixtures of any of the
foregoing. A specific, nonlimiting example of a synthetic polymeric
particle formed from an epoxy material is an epoxy microgel
particle. As used herein, a "thermoset" material is a material that
material solidifies or "sets" irreversibly when heated. A thermoset
material has formed a crosslinked network. As used herein, a See R.
J. Perry "Applications for Cross-Linked Siloxane Particles"
Chemtech, February 1999 at pages 39-44. polymeric material is
"crosslinked" if it at least partially forms a polymeric network.
One skilled in the art will understand that the presence and degree
of crosslinking (crosslink density) can be determined by a variety
of methods, such as dynamic mechanical thermal analysis (DMTA)
using a TA Instruments DMA 2980 analyzer conducted under nitrogen
such as is described above. This method determines the glass
transition temperature and crosslink density of free films of
coatings or polymers. These physical properties of a cured material
are related to the structure of the crosslinked network.
[0177] The particles also can be hollow particles formed from
materials selected from polymeric and nonpolymeric inorganic
materials, polymeric and nonpolymeric organic materials, composite
materials, and mixtures of any of the foregoing. Nonlimiting
examples of suitable materials from which the hollow particles can
be formed are described above.
[0178] In an embodiment of the present invention, the at least one
polysiloxane (a) is nonreactive with the particles.
[0179] In one embodiment, the present invention is directed to any
composition as previously described wherein the particles, when
added to the other components that form the composition, are
present in the composition in an amount ranging from 0.01 to 75
weight percent based on the total weight of the resin solids of the
components which form the composition. In another embodiment, the
present invention is directed to any composition as previously
described wherein the particles, when added to the other components
that form the composition, are present in the composition in an
amount of at least 0.1 weight percent, can be present in the
composition in an amount greater than 0.5 weight percent, and are
typically present in the composition in an amount greater than 5
weight percent based on the total weight of the resin solids of the
components which form the composition.
[0180] In yet another embodiment, the present invention is directed
to any composition as previously described wherein, the particles,
when added to the other components of the composition, are present
in the composition in an amount less than 75 weight percent, can be
present in the composition in an amount less than 50 weight
percent, can be present in the composition in an amount less than
20 weight percent, and are typically present in the composition in
an amount less than 10 weight percent based on the total weight of
the resin solids of the components which form the composition. The
amount of the particles present in the compositions may range
between any combination of these values inclusive of the recited
values.
[0181] Prior to incorporation, one class of particles which can be
used according to the present invention includes sols, such as an
organosol, of the particles. These sols can be of a wide variety of
small-particle, colloidal silicas having an average particle size
in ranges such as identified above.
[0182] The colloidal silicas can be surface modified during or
after the particles are initially formed. These surface modified
silicas may contain on their surface chemically bonded
carbon-containing moieties, as well as such groups as anhydrous
SiO.sub.2 groups and SiOH groups, various ionic groups physically
associated or chemically bonded within the surface of the silica,
adsorbed organic groups, or combinations of any of the foregoing,
depending on the characteristics of the particular silica desired.
Such surface modified silicas are described in detail in U.S. Pat.
No. 4,680,204, which is incorporated herein by reference.
[0183] Such materials can be prepared by a variety of techniques in
various forms, nonlimiting examples comprise organosols and mixed
sols. As used herein the term "mixed sols" is intended to include
those dispersions of colloidal silica in which the dispersing
medium comprises both an organic liquid and water. Such small
particle colloidal silicas are readily available, are essentially
colorless and have refractive indices which permit their inclusion
in compositions that, without additional pigments or components
known in the art to color or decrease the transparency of such
compositions, result in colorless, transparent coatings.
[0184] Suitable nonlimiting examples of particles include colloidal
silicas, such as those commercially available from Nissan Chemical
Company under the trademark ORGANOSILICASOLS.TM. such as
ORGANOSILICASOLTM MT-ST, and from Clariant Corporation as
HIGHLINK.TM.; colloidal aluminas, such as those commercially
available from Nalco Chemical under the trademark NALCO 8676.RTM.;
and colloidal zirconias, such as those commercially available from
Nissan Chemical Company under the trademark HIT-32M.RTM..
[0185] The particles can be incorporated into the compositions of
the invention in the form of a stable dispersion. When the
particles are in a colloidal form, the dispersions can be prepared
by dispersing the particles in a carrier under agitation and
solvent that is present can be removed under vacuum at ambient
temperatures. In certain embodiments, the carrier can be other than
a solvent, such as the surface active agents described in detail
below, including, but not limited to a polysiloxane containing
reactive functional groups, including, but not limited to, the at
least one polysiloxane Alternatively, the dispersions can be
prepared as described in U.S. Pat. Nos. 4,522,958 or 4,526,910,
which are incorporated by reference herein. The particles can be
"cold-blended" with the at least one polysiloxane (a) prior to
incorporation into the inventive compositions. Alternatively, the
particles can be post-added to an admixture of any remaining
composition components (including, but not limited to, the at least
one polysiloxane (a)) and dispersed therein using dispersing
techniques well-known in the art.
[0186] When the particles are in other than colloidal form, for
example, but not limited to, agglomerate form, the dispersions can
be prepared by dispersing the agglomerate in the carrier, for
example, but not limited to, the at least one polysiloxane (a), to
stably disperse the particles therein. Dispersion techniques such
as grinding, milling, microfluidizing, ultrasounding,, or any other
pigment dispersing techniques well known in the art of coatings
formulation can be used. Alternatively, the particles can be
dispersed by any other dispersion techniques known in the art. If
desired, the particles in other than colloidal form can be
post-added to an admixture of other composition components and
dispersed therein using any dispersing techniques known in the
art.
[0187] The particles can be present in a dispersion, suspension or
emulsion in a carrier. Nonlimiting examples of suitable carriers
include, but are not limited to, water, solvents, surfactants, or a
mixture of any of the foregoing.
[0188] In yet another embodiment of the present invention, at least
one adjuvant surface active agent can be present during the
formation of the compositions as previously described. Further, as
used herein, by "surface active agent" is meant any material which
tends to lower the solid surface tension or surface energy of the
"cured" composition or coating. That is, the cured composition or
coating formed from a composition comprising a surface active agent
has a lower solid surface tension or surface energy than a cured
coating formed from the analogous composition which does not
contain the surface active agent.
[0189] For purposes of the present invention, solid surface tension
can be measured according to the Owens-Wendt method using a
Rame'-Hart Contact Angle Goniometer with distilled water and
methylene iodide as reagents. Generally, a 0.02 cc drop of one
reagent is placed upon the cured coating surface and the contact
angle and its complement are measured using a standard microscope
equipped with the goniometer. The contact angle and its complement
are measured for each of three drops. The process is then repeated
using the other reagent. An average value is calculated for the six
measurements for each of the reagents. The solid surface tension is
then calculated using the Owens-Wendt equation:
{.gamma.I(1+cos.PHI.)}/2=(.gamma.I.sup.d.gamma..sub.s.sup.d).sup.1/2+(.gam-
ma.I.sup.p.sub.s.sup.p).sup.1/2
[0190] where .gamma.I is the surface tension of the liquid
(methylene iodide=50.8, distilled water=72.8) and .gamma..sup.d and
.gamma..sup.p are the dispersion and polar components (methylene
iodide .gamma..sup.d=49.5, .gamma..sup.p=1.3; distilled water
.gamma..sup.d=21.8, .gamma..sup.p=51.0); the values for .PHI.
measured and the cos .PHI. determined. Two equations are then
setup, one for methylene iodide and one for water. The only
unknowns are .gamma..sub.s.sup.d and .gamma..sub.s.sup.p. The two
equations are then solved for the two unknowns. The two components
combined represent the total solid surface tension.
[0191] The at least one adjuvant surface active agent can be
selected from amphiphilic, reactive functional group-containing
polysiloxanes such as are described above, amphiphilic
fluoropolymers, and mixtures of any of the foregoing. With
reference to water-soluble or water-dispersible amphiphilic
materials, the term "amphiphilic" means a polymer having a
generally hydrophilic polar end and a water-insoluble generally
hydrophobic end. Nonlimiting examples of suitable functional
group-containing polysiloxanes for use as surface active agents
include those polysiloxanes described above. Nonlimiting examples
of suitable amphiphilic fluoropolymers include fluoroethylene-alkyl
vinyl ether alternating copolymers (such as those described in U.S.
Pat. No. 4,345,057) available from Asahi Glass Company under the
tradename LUMIFLON; fluorosurfactants, such as the fluoroaliphatic
polymeric esters commercially available from 3M of St. Paul, Minn.
under the tradename FLUORAD; functionalized perfluorinated
materials, such as 1H,1H-perfluoro-nonanol commercially available
from FluoroChem USA; and perfluorinated (meth)acrylate resins.
[0192] Nonlimiting examples of other adjuvant surface active agents
suitable for use in the composition or coating of the present
invention can include anionic, nonionic and cationic surface active
agents.
[0193] Nonlimiting examples of suitable anionic surface active
agents include sulfates or sulfonates. Specific nonlimiting
examples include higher alkyl mononuclear aromatic sulfonates such
as the higher alkyl benzene sulfonates containing from 10 to 16
carbon atoms in the alkyl group and a straight- or branched-chain,
e.g., the sodium salts of decyl, undecyl, dodecyl, tridecyl,
tetradecyl, pentadecyl or hexadecyl benzene sulfonate and the
higher alkyl toluene, xylene and phenol sulfonates; alkyl
naphthalene sulfonate, and sodium dinonyl naphthalene sulfonate.
Other nonlimiting examples of suitable anionic surface active
agents include olefin sulfonates, including long chain alkenylene
sulfonates, long chain hydroxyalkane sulfonates, and mixtures of
any of the foregoing. Nonlimiting examples of other sulfate or
sulfonate detergents are paraffin sulfonates such as the reaction
products of alpha olefins and bisulfites (e.g., sodium bisulfite).
Also comprised are sulfates of higher alcohols, such as sodium
lauryl sulfate, sodium tallow alcohol sulfate, or sulfates of
mono-or di-glycerides of fatty acids (e.g., stearic monoglyceride
monosulfate), alkyl poly(ethoxy)ether sulfates including, but not
limited to, the sulfates of the condensation products of ethylene
oxide and lauryl alcohol (usually having 1-5 ethenoxy groups per
molecule); lauryl or other higher alkyl glyceryl ether sulfonates;
aromatic poly(ethenoxy)ether sulfates including, but not limited
to, the sulfates of the condensation products of ethylene oxide and
nonyl phenol (usually having 1-20 oxyethylene groups .degree. per
molecule). Further nonlimiting examples include salts of sulfated
aliphatic alcohol, alkyl ether sulfate or alkyl aryl ethoxy sulfate
available from Rhone-Poulenc under the general tradename ABEX.
Phosphate mono-or di-ester type anionic surface active agents also
can be used. These anionic surface active agents are well known in
the art and are commercially available under the general trade
designation GAFAC from GAF Corporation and under the general trade
designation TRITON from Rohm & Haas Company.
[0194] Nonlimiting examples of nonionic surface active agents
suitable for use in the cured composition or coating of the present
invention include those containing ether linkages and which are
represented by the following general formula: RO(R'O).sub.nH;
wherein the substituent group R represents a hydrocarbon group
containing 6 to 60 carbon atoms, the substituent group R'
represents an alkylene group containing 2 or 3 carbon atoms, and
mixtures of any of the foregoing, and n is an integer ranging from
2 to 100. Such nonionic surface active agents can be prepared by
treating fatty alcohols or alkyl-substituted phenols with an excess
of ethylene or propylene oxide. The alkyl carbon chain may contain
from 14 to 40 carbon atoms and may be derived from a long chain
fatty alcohol such as oleyl alcohol or stearyl alcohol. Nonionic
polyoxyethylene surface active agents of the type represented by
the formula above are commercially available under the general
trade designation SURFYNOL.RTM. from Air Products Chemicals, Inc.;
PLURONIC.RTM. or TETRONIC.RTM. from BASF Corporation; TERGITOL.RTM.
from Union Carbide; and SURFONIC.RTM. from Huntsman Corporation.
Other nonlimiting examples of suitable nonionic surface active
agents include block copolymers of ethylene oxide and propylene
oxide based on a glycol such as ethylene glycol or propylene glycol
including, but not limited to, those available from BASF
Corporation under the general trade designation PLURONIC.RTM..
[0195] As indicated above, cationic surface active agents also can
be used. Nonlimiting examples of cationic surface active agents
suitable for use in the compositions of the present invention
include acid salts of alkyl amines such as ARMAC.RTM. HT, an acetic
acid salt of n-alkyl amine available from Akzo Nobel Chemicals;
imidazoline derivatives such as CALGENE.RTM. C-100 available from
Calgene Chemicals Inc.; ethoxylated amines or amides such as
DETHOX.RTM. Amine C-5, a cocoamine ethoxylate available from
Deforest Enterprises; ethoxylated fatty amines such as ETHOX.RTM.
TAM available from Ethox Chemicals, Inc.; and glyceryl esters such
as LEXEMUL.RTM. AR, a glyceryl stearate/stearaidoethyl diethylamine
available from Inolex Chemical Co.
[0196] Other examples of suitable surface active agents can include
polyacrylates. Nonlimiting examples of suitable polyacrylates
include homopolymers and copolymers of acrylate monomers, for
example polybutylacrylate and copolymers derived from acrylate
monomers (such as ethyl (meth)acrylate, 2-ethylhexylacrylate, butyl
(meth)acrylate and isobutyl acrylate), and hydroxy
ethyl(meth)acrylate and (meth)acrylic acid monomers. In one
embodiment, the polyacrylate can have amino and hydroxy
functionality. Suitable amino and hydroxyl functional acrylates are
disclosed in Example 26 below and in U.S. Pat. No. 6,013,733, which
is incorporated herein by reference. Another example of a useful
amino and hydroxyl functional copolymer is a copolymer of hydroxy
ethyl acrylate, 2-ethylhexylacrylate, isobutyl acrylate and
dimethylamino ethylmethacrylate. In another embodiment, the
polyacrylate can have acid functionality, which can be provided,
for example, by including acid functional monomers such as
(meth)acrylic acid in the components used to prepare the
polyacrylate. In another embodiment, the polyacrylate can have acid
functionality and hydroxyl functionality, which can be provided,
for example, by including acid functional monomers such as
(meth)acrylic acid and hydroxyl functional monomers such as hydroxy
ethyl (meth)acrylate in the components used to prepare the
polyacrylate.
[0197] Suitable flow additives include silicones such as BYK 310 or
BYK 307, which are commercially available from Byk-Chemie. Suitable
rheology control agents include cellulose acetate butyrate and
fumed silicas such as R812 which is commercially available from
Degussa Chemical.
[0198] In yet another embodiment, the present invention is directed
to a coated substrate comprising a substrate and a composition
coated over at least a portion of the substrate, wherein the
composition is selected from any of the foregoing compositions. In
still another embodiment, the present invention is directed to a
method of coating a substrate which comprises applying a
composition over at least a portion of the substrate, wherein the
composition is selected from any of the foregoing compositions. In
another embodiment, the present invention is directed to a method
of coating a substrate further comprising a step of curing the
composition after application to the substrate. The components used
to form the compositions in these embodiments can be selected from
the components discussed above, and additional components also can
be selected from those recited above.
[0199] As used herein, a composition "over" at least a portion of a
substrate refers to a composition directly applied to at least a
portion of the substrate, as well as a composition applied to any
coating or adhesion promoter material which was previously applied
to at least a portion of the substrate.
[0200] The coating compositions of the present invention can be
applied over virtually any flexible substrate including plastic,
and polymeric substrates such as elastomeric substrates. In one
embodiment, the present invention is directed to a coated substrate
as previously described wherein the coated substrate is a flexible
elastomeric substrate. In still another embodiment, the present
invention is directed to coated substrates as previously described
wherein the coated substrate is a polymeric substrate. The
components used to form the compositions in these embodiments can
be selected from the components discussed above, and additional
components also can be selected from those recited above.
[0201] A further embodiment of the present invention is directed to
a coated automobile substrate comprising an automobile substrate
and a composition coated over at least a portion of the automobile
substrate, wherein the composition is selected from any of the
foregoing compositions. In yet another embodiment, the present
invention is directed to a method of making a coated automobile
substrate comprising providing an automobile substrate and applying
over at least a portion of the automotive substrate a composition
selected from any of the foregoing compositions. Again, the
components used to form the compositions in these embodiments can
be selected from the components discussed above, and additional
components also can be selected from those recited above.
[0202] Suitable polymeric or flexible elastomeric substrates can
include any of the thermoplastic or thermoset synthetic materials
well known in the art. Nonlimiting examples of suitable flexible
elastomeric substrate materials include polyethylene,
polypropylene, thermoplastic polyolefin ("TPO"), reaction injected
molded polyurethane ("RIM") and thermoplastic polyurethane
("TPU").
[0203] Nonlimiting examples of thermoset materials useful as
substrates in connection with the present invention include
polyesters, epoxides, phenolics, polyurethanes such as "RIM"
thermoset materials, and mixtures of any of the foregoing.
Nonlimiting examples of suitable thermoplastic materials include
thermoplastic polyolefins such as polyethylene, polypropylene,
polyamides such as nylon, thermoplastic polyurethanes,
thermoplastic polyesters, acrylic polymers, vinyl polymers,
polycarbonates, acrylonitrile-butadiene-styrene ("ABS") copolymers,
ethylene propylene diene terpolymer ("EPDM") rubber, copolymers,
and mixtures of any of the foregoing.
[0204] If desired, the polymeric substrates described above can
have an adhesion promoter present on the surface of the substrate
over which the coating compositions of the present invention are
applied. To facilitate adhesion of organic coatings to polymeric
substrates, the substrate can be pretreated using an adhesion
promoter layer or tie coat, e.g., a thin layer 0.25 mils (6.35
microns) thick, or by flame or corona pretreatment.
[0205] Suitable adhesion promoters include chlorinated polyolefin
adhesion promoters such as are described in U.S. Pat. Nos.
4,997,882; 5,319,032; and 5,397,602, incorporated by reference
herein. Other useful adhesion promoting coatings are disclosed in
U.S. Pat. No. 6,001,469 (a coating composition containing a
saturated polyhydroxylated polydiene polymer having terminal
hydroxyl groups), U.S. Pat. No. 5,863,646 (a coating composition
having a blend of a saturated polyhydroxylated polydiene polymer
and a chlorinated polyolefin) and U.S. Pat. No. 5,135,984 (a
coating composition having an adhesion promoting material obtained
by reacting a chlorinated polyolefin, maleic acid anhydride, acryl
or methacryl modified hydrogenated polybutadiene containing at
least one acryloyl group or methacryloyl group per unit molecule,
and organic peroxide), which are incorporated herein by
reference.
[0206] When the substrates are used as components to fabricate
automotive vehicles (including, but not limited to, automobiles,
trucks and tractors) they can have any shape, and can be selected
from the flexible substrates described above. Typical shapes of
automotive body components can include body side moldings, fenders,
bumpers, and trim for automotive vehicles.
[0207] In a further embodiment, the present invention is directed
to coated automotive substrates as previously described wherein the
coated automotive substrate is a body side molding. In another
embodiment, the present invention is directed to coated automotive
substrates as previously described wherein the coated automotive
substrate is a fender. In another embodiment, the present invention
is directed to coated automotive substrates as previously described
wherein the coated automotive substrate is a bumper. In another
embodiment, the present invention is directed to coated automotive
substrates as previously described wherein the coated automotive
substrate is trim. The components used to form the compositions
used to coat the automotive substrates in these embodiments can be
selected from the components discussed above, and additional
components also can be selected from those recited above.
[0208] In another embodiment, the present invention is directed to
multi-component composite coating compositions comprising a
basecoat deposited from a base coating composition, which,
typically is pigmented, and a topcoat deposited from any of the
coating compositions of the present invention previously described
above. In one embodiment, the present invention is directed to a
multi-component composite coating composition as previously
described, wherein the topcoating composition is transparent after
curing and is selected from any of the compositions previously
described. The components used to form the topcoating composition
in these embodiments can be selected from the coating components
discussed above, and additional components also can be selected
from those recited above.
[0209] The basecoat and transparent topcoat (i.e., clearcoat)
compositions used in the multi-component composite coating
compositions of the present invention in certain instances can be
formulated into liquid high solids coating compositions, that is,
compositions containing 40 percent, or greater than 50 percent by
weight resin solids. The solids content can be determined by
heating a sample of the composition to 105.degree. C. to
110.degree. C. for 1-2 hours to drive off the volatile material,
and subsequently measuring relative weight loss. As aforementioned,
although the compositions can be liquid coating compositions, they
also can be formulated as powder coating compositions.
[0210] The coating composition of the basecoat in the
color-plus-clear system can be any of the compositions useful in
coatings applications, particularly automotive applications. The
coating composition of the basecoat can comprise a resinous binder
and a pigment to act as the colorant. Nonlimiting examples of
resinous binders are acrylic polymers, polyesters, alkyds, and
polyurethanes.
[0211] The resinous binders for the basecoat can be organic
solvent-based materials such as those described in U.S. Pat. No.
4,220,679, note column 2, line 24 continuing through column 4, line
40, which portions are incorporated by reference. Also, water-based
coating compositions such as those described in U.S. Pat. Nos.
4,403,003, 4,147,679 and 5,071,904 can be used as the binder in the
basecoat composition. These U.S. patents are incorporated herein by
reference.
[0212] The basecoat composition can comprise one or more pigments
as colorants. Nonlimiting examples of suitable metallic pigments
include aluminum flake, copper bronze flake, and metal oxide coated
mica.
[0213] Besides the metallic pigments, the basecoat compositions can
contain nonmetallic color pigments conventionally used in surface
coatings such as, for example, inorganic pigments such as titanium
dioxide, iron oxide, chromium oxide, lead chromate, and carbon
black; and organic pigments such as phthalocyanine blue and
phthalocyanine green.
[0214] Optional ingredients in the basecoat composition can
comprise those which are well known in the art of formulating
surface coatings and can comprise surface active agents, flow
control agents, thixotropic agents, fillers, anti-gassing agents,
organic co-solvents, catalysts, and other customary auxiliaries.
Nonlimiting examples of these materials and suitable amounts are
described in U.S. Pat. Nos. 4,220,679; 4,403,003; 4,147,769; and
5,071,904, which patents are incorporated herein by reference.
[0215] The basecoat compositions can be applied to the substrate by
any conventional coating technique such as brushing, spraying,
dipping, or flowing. Spray techniques and equipment for air
spraying, airless spray, and electrostatic spraying in either
manual or automatic methods, known in the art can be used.
[0216] During application of the basecoat to the substrate, the
film thickness of the basecoat formed on the substrate can range
from 0.1 to 5 mils. In another embodiment, the film thickness of
the basecoat formed on the substrate can range 0.1 to 1 mils, and
can be 0.4 mils.
[0217] After forming a film of the basecoat on the substrate, the
basecoat can be cured or alternatively given a drying step in which
solvent is driven out of the basecoat film by heating or an air
drying period before application of the clearcoat. Suitable drying
conditions may depend on the particular basecoat composition, and
on the ambient humidity if the composition is water-borne, but a
drying time from 1 to 15 minutes at a temperature of 75.degree. to
200.degree. F. (21.degree. to 93.degree. C.) can be adequate.
[0218] The transparent or clear topcoat composition can be applied
to the basecoat by any conventional coating technique, including,
but not limited to, -compressed air spraying, electrostatic
spraying, and either manual or automatic methods. The transparent
topcoat can be applied to a cured or to a dried basecoat before the
basecoat has been cured. In the latter instance, the two coatings
can then be heated to cure both coating layers simultaneously.
Typical curing conditions can range from 50.degree. F. to
475.degree. F. (10C to 246.degree. F.) for 1 to 30 minutes. The
clearcoating thickness (dry film thickness) can be 1 to 6 mils.
[0219] A second topcoat coating composition can be applied to the
first topcoat to form a "clear-on-clear" topcoat. The first topcoat
coating composition can be applied over the basecoat as described
above. The second topcoat coating composition can be applied to a
cured or to a dried first topcoat before the basecoat and first
topcoat have been cured. The basecoat, the first topcoat and the
second topcoat can then be heated to cure the three coatings
simultaneously.
[0220] It should be understood that the second transparent topcoat
and the first transparent topcoat coating compositions can be the
same or different provided that, when applied wet-on-wet, one
topcoat does not substantially interfere with the curing of the
other for example by inhibiting solvent/water evaporation from a
lower layer. Moreover, the first topcoat, the second topcoat or
both can be the film-forming composition of the present invention.
The first transparent topcoat coating composition can be virtually
any transparent topcoating composition known to those skilled in
the art. The first transparent topcoat composition can be
water-borne or solventborne, or, alternatively, in solid
particulate form, i.e., a powder coating.
[0221] Nonlimiting examples of suitable first topcoating
compositions include crosslinkable coating compositions comprising
at least one thermosettable coating material and at least one
curing agent. Suitable waterborne clearcoats are disclosed in U.S.
Pat. No. 5,098,947 (incorporated by reference herein) and are based
on water-soluble acrylic resins. Useful solvent borne clearcoats
are disclosed in U.S. Pat. Nos. 5,196,485 and 5,814,410
(incorporated by reference herein) and include polyepoxides and
polyacid curing agents. Suitable powder clearcoats are described in
U.S. Pat. No. 5,663,240 (incorporated by reference herein) and
include epoxy functional acrylic copolymers and polycarboxylic acid
curing agents.
[0222] Typically, after forming the first topcoat over the
basecoat, the first topcoat is given a drying step in which solvent
is driven out of the film by heating or, alternatively, an air
drying period or curing step before application of the second
topcoat. Suitable drying conditions will depend on the particular
first topcoat composition, and on the ambient humidity if the
composition is water-borne, but, in general, a drying time from 1
to 15 minutes at a temperature of 75.degree. F. to 200.degree. F.
(21.degree. C. to 93.degree. C.) will be adequate.
[0223] The film-forming composition of the present invention when
employed as a second topcoat coating composition can be applied as
described above for the first topcoat by any conventional coating
application technique. Curing conditions can be those described
above for the topcoat. The second topcoating dry film thickness can
range from 0.1 to 3 mils (7.5 micrometers to 75 micrometers).
[0224] It should be mentioned that the coating compositions of the
present invention can be advantageously formulated as a "monocoat",
that is a coating which forms essentially one coating layer when
applied to a substrate. The monocoat coating composition can be
pigmented. Nonlimiting examples of suitable pigments include those
mentioned above. When employed as a monocoat, the coating
compositions of the present invention can be applied (by any of the
conventional application techniques discussed above) in two or more
successive coats, and, in certain instances can be applied with
only an ambient flash period between coats. The multi-coats when
cured can form essentially one coating layer.
[0225] In another embodiment, the coating compositions of the
present invention also can be useful as decorative or protective
coatings for pigmented plastic (elastomeric) substrates, such as
those described above, or mold-in-color ("MIC") plastic substrates.
In these applications, the compositions can be applied directly to
the plastic substrate or included in the molding matrix.
Optionally, an adhesion promoter can first be applied directly to
the plastic or elastomeric substrate and the composition applied as
a topcoat thereover, as discussed above. The compositions of the
present invention also can be advantageously formulated as
pigmented coating compositions for use as primer coatings, as
basecoats in multi-component composite coatings, and as monocoat
topcoats including pigments or colorants. The components used to
form the compositions in these embodiments can be selected from the
coating components discussed above, and additional components also
can be selected from those recited above.
[0226] In embodiments of the present invention directed to
automotive applications, the cured compositions can be, for
example, the electrodeposition coating, the primer coating, the
basecoat, and/or the topcoat. Suitable topcoats include monocoats
and basecoat/clearcoat composites. Monocoats are formed from one or
more layers of a colored coating composition. Basecoat/clearcoat
composites comprise one or more layers of a colored basecoat
composition, and one or more layers of a clearcoating composition,
wherein the basecoat composition has at least one component which
is different from the clearcoat composition. In the embodiments of
the present invention directed to automotive applications, the
clearcoat can be transparent after application.
[0227] In another embodiment, the present invention is directed to
a method for making a multi-component composite comprising (a)
applying a pigmented composition to a substrate to form a basecoat;
and (b) applying a topcoating composition over at least a portion
of the basecoat to form a topcoat thereon, wherein the topcoating
composition is selected from any of the compositions described
above. The components used to form the topcoating composition in
this embodiment can be selected from the coating components
discussed above, and additional components also can be selected
from those recited above.
[0228] In one embodiment, the present invention is directed to a
method of repairing a multi-layer composite coating comprising a
base coat formed on a substrate from a film-forming base coating
composition and a first top coat deposited over at least a portion
of the base coat, the first top coat formed from a first
film-forming top coating composition comprising any of the
foregoing coating compositions, the method comprising locating an
area of the composite coating which is flawed, and applying a
repair top coat film-forming composition to the flawed area after
the flawed area has been prepared for repairing. The repair top
coat film-forming composition can comprise a film-forming
composition which is the same or different from the first top coat
film-forming composition. The flawed area can be any coating
blemish that cannot be polished out, for example dirt particles in
the coating surface. The flawed area typically can be abraded or
sanded to remove such coating blemishes. In a repair carried out in
accordance with the method of the present invention, the first top
coating can provide excellent intercoat adhesion with the
subsequently applied repair top coating.
[0229] The coatings formed from the compositions according to the
present invention can have outstanding appearance properties and
initial scratch (mar) resistance properties, as well as
post-weathering or "retained" scratch (mar) resistance, which can
be evaluated by measuring the gloss of coated substrates before and
after abrading of the coated substrates. Moreover, the coatings
formed from the compositions according to the present invention can
have excellent intercoat adhesion, both to previously applied
coatings as well as to subsequently applied coatings.
[0230] In one embodiment, the present invention is directed to
methods of improving the scratch resistance of a polymeric
substrate or polymer coated substrate comprising applying to at
least a portion of the substrate any of the previously described
inventive compositions, and curing the composition to form a cured
coating on the substrate.
[0231] In another embodiment, the present invention is directed to
a method for retaining the gloss of a polymeric substrate or
polymer coated substrate after a predetermined period of time
comprising applying to the substrate comprising any of the
inventive compositions described for the substrate. This
predetermined period of time can generally be at least 6 months and
can be at least one year. In another embodiment, the present
invention is directed to a method for revitalizing the gloss of a
polymeric substrate or polymer coated substrate comprising applying
to the substrate any of the inventive compositions described
above.
[0232] The initial 20.degree. gloss of a cured coated substrate
according to the present invention can be measured with a
20.degree. NOVO-GLOSS 20 statistical glossmeter, available from
Gardner Instrument Company, Inc. The coated substrate can be
subjected to scratch testing by linearly scratching the coating or
substrate with a weighted abrasive paper for ten double rubs using
an Atlas AATCC Scratch Tester, Model CM-5, available from Atlas
Electrical Devices Company of Chicago, Illinois. The abrasive paper
is 3M 281 Q WETORDRY.TM. PRODUCTION.TM. 9 micron polishing paper
sheets, which are commercially available from 3M Company of St.
Paul, Minn. Panels are then rinsed with tap water and carefully
patted dry with a paper towel. The 200 gloss is measured on the
scratched area of each test panel. The number reported is the
percent of the initial gloss retained after scratch testing, i.e.,
100%.times.scratched gloss/initial gloss. This test method is fully
disclosed in the examples that follow.
[0233] In certain embodiments, the cured composition or coating of
the present invention has an initial 200 gloss (as measured using a
200 NOVO-GLOSS 20 statistical glossmeter, available from Gardner
Instrument Company) of greater than 40, can be greater than 50, and
is often greater than 70. This high gloss composition can be
curable under ambient or thermal conditions or by radiation curing
techniques, for example, by actinic radiation. In one embodiment,
the high gloss composition is curable by ambient or thermal
conditions.
[0234] Moreover, the cured topcoat formed from the compositions of
the present invention can exhibit excellent initial scratch (mar)
resistance, as well as post-weathering scratch (mar) resistance
properties. The cured topcoat can have an initial scratch (mar)
resistance value (as measured by first determining the initial
20.degree. gloss as described above, linearly abrading the cured
coating surface with a weighted abrasive paper for ten double rubs
using an Atlas AATCC Scratch Tester, Model CM-5, available from
Atlas Electrical Devices Company, and measuring the 20.degree.
gloss as described above for the abraded surface) such that after
scratch (mar) testing greater than 30 percent of initial 20.degree.
gloss is retained, in certain instances greater than 40 percent of
initial 20.degree. gloss is retained, and in other instances
greater than 60 percent of initial 20.degree. gloss is retained
after abrading the coating surface (that is, 100%.times.scratched
gloss/initial gloss).
[0235] Also, the cured topcoat formed from the compositions of the
present invention can have a post-weathering scratch (mar)
resistance (as measured using the scratch test method described
above after the unscratched test panels were subjected to simulated
weathering by QUV exposure to UVA-340 bulbs in a weathering cabinet
available from Q Panel Company) such that greater than 30 percent
of initial 20.degree. gloss is retained is retained after
weathering for 250 hours. In another embodiment, greater than 50
percent of initial 20.degree. gloss is retained, an often greater
than 70 percent of initial 20.degree. gloss is retained after
weathering for 250 hours.
[0236] The compositions of the present invention can advantageously
be used to form the transparent topcoat (i.e., clearcoat) in a
cured multi-component composite coating comprising a basecoat
deposited from a pigmented coating composition and the topcoat
deposited from a topcoat coating composition. As used herein,
"transparent" means that the cured coating has a BYK Haze index of
less than 50 as measured using a BYK Haze/Gloss Instrument. When so
employed, the cured topcoat can be deposited from any of the
previously described compositions of the present invention.
[0237] The coating compositions of the present invention can
provide flexible cured coatings. Flexibility testing can be
conducted according to the following "Flexibility Test Method." The
coating is applied to a flexible polymeric test panel and cured.
For flex testing, a 1-inch by 4-inch piece is cut from the coated
test panel. At a temperature of 70.degree. F. (21.degree.
C.).+-.5.degree. F., the piece is subjected to a mandrel bend using
a 1/2 inch diameter steel mandrel, such that the two ends of the
4-inch long test piece contacted one another. The test panel is
then rated for flexibility by visual inspection for coating
cracking on a scale of 0 to 10. A "10" rating is recorded where
there is no visible paint cracking; a "9" rating has less than five
interrupted short line cracks; an "8" has interrupted line cracks
with a maximum of four uninterrupted line cracks; a "6" has five to
ten uninterrupted line cracks; a "4" has more than 15 uninterrupted
line cracks; and a "0" represents fracture of the substrate. In one
embodiment, the coating compositions when cured have a flexibility
rating of at least 6 at 70.degree. F. In another embodiment, the
coating compositions when cured have a flexibility rating of at
least 8 at 70.degree. F, while in yet another embodiment, the
coating compositions when cured have a flexibility rating of at
least 9 at 70.degree. F.
[0238] Moreover, the coating compositions of the present invention
can provide cured coatings having excellent intercoat or interlayer
adhesion to subsequently applied coating layers. For example, any
of the aforementioned coating compositions can be applied as a
transparent clearcoat in a color-plus-clear coating system as
discussed above. In the event of damage to the cured coating system
causing a surface defect, it may be necessary to prepare the
damaged area for repair with a subsequently applied clear coat
composition. The coating compositions of the present invention can
provide excellent intercoat adhesion between the first clear coat
layer and the subsequently applied repair clear coat layer.
Likewise, when used as a top coat composition, the coating
compositions of the present invention also provide excellent
interlayer adhesion between the cured top coat and a subsequently
applied windshield adhesive without the intervening step of
applying an adhesion promoting primer.
[0239] Illustrating the invention are the following examples which,
however, are not to be considered as limiting the invention to
their details. Unless otherwise indicated, all parts and
percentages in the following examples, as well as throughout the
specification, are by weight.
EXAMPLES
Resin Compositions
Polysiloxane Polyol
Example AA
[0240] This example describes the preparation of a polysiloxane
polyol which was subsequently used to form respective silica
dispersions of Examples A and B, and the polysiloxane borates used
in the thermosetting compositions of the present invention. The
polysiloxane polyol was a product of the hydrosilylation of a
reactive silicone fluid having an approximate degree of
polymerization of 3 to 7, i.e., (Si--O).sub.3 to (Si--O).sub.7. The
polysiloxane polyol was prepared from a proportionately scaled-up
batch of the following mixture of ingredients in the ratios
indicated:
2 Parts by Equivalent Weight Ingredients Weight Equivalents
(kilograms) Charge I: Trimethylolpropane monoallyl 174.0 756.0
131.54 ether Charge II: MASILWAX BASE.sup.1 156.7.sup.2 594.8 93.21
Charge III: 10 ppm Chloroplatinic acid 0.23 Toluene 0.07
Isopropanol .sup.1Polysiloxane-containing silicon hydride,
commercially available from BASF Corporation. .sup.2Equivalent
weight based on mercuric bichloride determination.
[0241] To a suitable reaction vessel equipped with a means for
maintaining a nitrogen blanket, Charge I and an amount of sodium
acetate equivalent to 20to 25 ppm of total monomer solids was added
at ambient conditions and the temperature was gradually increased
to 75.degree. C. under a nitrogen blanket. At that temperature,
about 5.0% of Charge II was added under agitation, followed by the
addition of Charge III, equivalent to 10 ppm of active platinum
based on total monomer solids. The reaction was then allowed to
exotherm to 95.degree. C. at which time the remainder of Charge II
was added at a rate such that the temperature did not exceed
95.degree. C. After completion of this addition, the reaction
temperature was maintained at 95.degree. C. and monitored by
infrared spectroscopy for disappearance of the silicon hydride
absorption band (Si--H, 2150 cm.sup.-1).
Silica Dispersions
Example A
[0242] This example describes the preparation of a colloidal silica
dispersion used as a component in the thermosetting compositions of
the present invention. The colloidal silica dispersion was prepared
as follows. A suitable reaction vessel was equipped for vacuum
distillation and flushed with N.sub.2. To the reaction flask was
added 3150 g of the polysiloxane polyol of Example M described
above, 4500 g of ORGANOSILICASOL.TM. MT-ST colloidal silica (which
is commercially available from Nissan Chemicals) and 1440 g of
methyl amyl ketone. The mean particle size of the silica particles
was about 10-20 nanometers, as disclosed at http//www.snowtex.com
/organo _types.html (Jun. 2, 2000), which is incorporated by
reference herein. The resulting mixture was vacuum distilled at
25.degree. C. for a period of 8 hours.
Example B
[0243] This example describes the preparation of a colloidal silica
dispersion used as a component in the thermosetting compositions of
the present invention. The colloidal silica dispersion was prepared
as follows. A 4-neck reaction flask equipped for vacuum
distillation was flushed with N.sub.2. To the reaction flask was
added 1501.4 g of the polysiloxane tetrol described above, 3752.9 g
of ORGANOSILICASOL.TM. MT-ST colloidal silica (which is
commercially available from Nissan Chemicals) and 900.6 g of methyl
amyl ketone. The resulting mixture was vacuum distilled at 70 mm Hg
and 31.degree. C.
Adhesion Promoter Compositions
[0244] The following Examples C through H describe the preparation
of various adhesion promoting compositions used in the coating
compositions of the present invention. Each adhesion promoting
composition was prepared as described below.
Example C
[0245] A four-neck reaction flask equipped with stirrer,
temperature probe, Dean Stark trap and reflux condenser was flushed
with N2. The following materials were charged to the flask and
blended under agitation: 180.4 g of the polysilxoane polyol of
Example AA, 300.9 g of isopropyl alcohol and 25.8 g of boric acid.
The mixture was heated to reflux at a temperature of 79.degree. C.,
and 200 ml of solvent was removed over 0.25 hours. The resulting
material was cooled and measured to have 49.8% solids and contained
3.0% water.
Example D
[0246] A four-neck reaction flask equipped with stirrer,
temperature probe, Dean Stark trap and reflux condenser was flushed
with N.sub.2. The following materials were charged to the flask and
blended under agitation: 3241.4 g of the polysiloxane polyol of
Example AA, 5415.3 g of isopropyl alcohol and 463.9 g of boric
acid. The mixture was heated to reflux at a temperature of 730C,
and 3607.7 g of solvent was removed over a period of 1.5 hours. The
resulting material was cooled and measured to have 56.0% solids and
contained 2.5% water.
Example E
[0247] A four-neck reaction flask equipped with stirrer,
temperature probe, Dean Stark trap and reflux condenser was flushed
with N.sub.2. The following materials were charged to the flask and
blended under agitation: 180.3 g of polysiloxane polyol of Example
AA, 300.7 g of isopropyl alcohol and 25.8 g of boric acid. The
mixture was heated to reflux at a temperature 79.degree. C., and
200 ml of solvent was removed over a period of 0.25 hours. The
resulting material was cooled and measured to have 49.5% solids and
contained 3.0% water.
Example F
[0248] A four-neck reaction flask equipped with stirrer,
temperature probe, Dean Stark trap and reflux condenser was flushed
with N.sub.2. The following materials were charged to the flask and
blended under agitation: 1575.5 g Dowanol PM, and 144.8 g of Boric
acid.sup.2. The mixture was heated to reflux at a temperature of
110C, and held for a period 2 hours. Thereafter, 632.3 g of solvent
was removed over a period of 0.5 hours. The resulting material was
cooled and measured to have 11.2% solids and contained 5.0%
water.
Example G
[0249] A four-neck reaction flask equipped with stirrer,
temperature probe, Dean Stark trap and reflux condenser was flushed
with N.sub.2. The following ingredients were charged to the flask
and blended under agitation: 454.7 g of acrylic polyol (prepared
from 14.5% butyl acrylate, 14.5% butyl methacrylate, 27.6%
isobornyl methacrylate, 22.6% hydroxypropyl methacrylate, 20.4%
hydroxyethyl methacrylate, and 0.4% acrylic acid, having a resin
solids of 69.7%, Mw 3227 and hydroxyl value of 101), 97.2 g of
isopropyl alcohol and 2.06 g of boric acid. The mixture was heated
to reflux at a temperature of 93.degree. C., and held for a period
of 1 hour. Thereafter, 62 g of solvent was removed over a period of
0.25 hours, The resulting material was cooled and measured 69.3%
solids and contained 0.1% water.
Example H
[0250] A four-neck reaction flask equipped with stirrer,
temperature probe, Dean Stark trap and reflux condenser was flushed
with N.sub.2. The following materials were charged to the flask and
blended under agitation: 360.5 g of the polysiloxane polyol of
Example AA, 601.7 g of isopropyl alcohol and 13.6 g of aluminum
isopropoxide (available from Aldrich Chemical Co.). The mixture was
heated to reflux at a temperature of 81.degree. C., and,
thereafter, 401.8 g of solvent was removed over a period of 1 hour.
The resulting material was cooled and measured to have 53.32%
solids
Thermosetting Coating Compositions
One Component Compositions
Example 1
[0251] This example describes the preparation of a resinous binder
pre-mix used in the one-package thermosetting coating compositions
of Examples 4-6 below. Each of the ingredients was added
sequentially and mixed under mild agitation.
3 Parts by weight Solid weight Ingredient (grams) (grams) Methyl
n-amyl ketone 18.0 -- Butyl Cellosolve .RTM. acetate.sup.1 18.0 --
Butyl Carbitol .RTM. acetate.sup.2 4.0 -- TINUVIN .RTM. 384.sup.3
1.58 1.50 TINUVIN .RTM. 400.sup.4 1.76 1.50 TINUVIN .RTM. 292.sup.5
0.40 0.40 TINUVIN .RTM. 123.sup.6 0.40 0.40 Silica dispersion of
Example A 13.2 10.0 LUWIPAL 018.sup.7 41.1 30.0 TACT.sup.8 9.4 5.0
Polybutyl acrylate.sup.9 0.50 0.30 Blocked acid catalyst.sup.10
2.50 1.00 .sup.12-Butoxyethyl acetate solventcommercially available
from Union Carbide Corp. .sup.22-(2-Butoxyethoxy) ethyl acetate
commercially available from Union Carbide Corp. .sup.3Substituted
benzotriazole UV light stabilizer commercially available from Ciba
Specialty Chemicals Corp. .sup.4Substituted triazine UV light
stabilizer commercially available from Ciba Specialty Chemicals
Corp. .sup.5Sterically hindered amine light stabilizer commercially
available from Ciba Specialty Chemicals Corp.
.sup.6Bis-(1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate
hindered aminoether light stabilizer available from Ciba Specialty
Chemicals Corp. .sup.7High imino, butylated melamine formaldehyde
resin commercially available from BASF Corp. .sup.8Tris (alkyl
carbamoyl) triazine available from Cytec Industries, Inc. The alkyl
substituent was mixed methyl and butyl. .sup.9A flow control agent
having a Mw of about 6700 and a Mn of about 2600 made in xylene at
62.5% solids available from E. I. duPont de Nemours and Company.
.sup.10Dodecyl benzene sulfonic acid solution, blocked with
diisopropanol amine to 91% total neutralization, 40 percent in
ethanol.
Example 2
[0252] This example describes the preparation of a resinous binder
pre-mix used in the one-package thermosetting coating composition
of Examples 7-9 described below. Each of the ingredients was added
sequentally and mixed under mild agitation.
4 Parts by weight Solid weight Ingredient (grams) (grams) Methyl
n-amyl ketone 16.0 -- Butyl Cellosolve .RTM. acetate 16.0 -- Butyl
Carbitol .RTM. acetate 3.50 -- TINUVIN .RTM. 928.sup.1 3.00 3.00
TINUVIN .RTM. 292 0.40 0.40 Silica Dispersion of Example B 10.3 7.0
RESIMENE .RTM. 757.sup.2 41.2 40.0 Polybutyl acrylate 0.50 0.30
Blocked acid catalyst 2.50 1.00
.sup.12-(2H-Benzotriazol-2y1)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetra-
methylbutyl)phenol UV absorber available from Ciba Specialty
Chemicals Corp. .sup.2Methylated and butylated
melamine-formaldehyde resin available from Cytec Industries,
Inc.
Example 3
[0253] This example describes the preparation of a resinous binder
pre-mix used in the preparation of thermosetting coating
compositions of Examples 7-9 described below. The resins were
admixed and blended under mild agitation.
5 Parts by weight Solid weight Ingredient (grams) (grams)
Carbamoylated acrylic.sup.1 44.4 28.0 Carbamoylated polyester.sup.2
38.9 28.0 .sup.1(58% butyl methacrylate/40% hydroxypropyl
acrylate/2% methyl styrene dimer) 64% solids in a solvent blend of
(50% DOWANOL PM/50% propanoic acid, 3-ethoxy ethyl ester), 75%
carbamoylated with methyl carbamate. .sup.2(10.6% trimethylol
propane/22.7% 2,2,4-trimethyl-1,3-pentanediol/17- .5% neopentyl
glycol/49.2% hexahydrophthalic anhydride) 69% solids in a solvent
blend of (44% Dowanol PM/56% Dowanol PM Acetate) 75% carbamoylated
with methyl carbamate.
[0254] The preparation of various one-package thermosetting coating
compositions are described below in the following Tables 1 and 2.
The amounts listed are the total parts by weight in grams and the
amount within parenthesis are percentages by weight based on weight
of solids. Each component was mixed sequentially with agitation.
Comparative coating compositions which do not contain a
boron-containing compound are indicated using an "*".
6TABLE 1 Ingredient Example 4* Example 5 Example 6 Example 1
pre-mix 110.8 (50.1) 110.8 (50.1) 110.8 (50.1) Acrylic resin.sup.1
89.9 (58.0) 88.4 (57.0) 83.7 (54.0) Siloxane Borate of -- 2.01
(1.00) 8.0 (4.00) Example C Reduction: Methyl n-amyl ketone 5.4
4.79 3.07 Butyl Cellosolve .RTM. 5.4 4.79 3.07 acetate Butyl
Carbitol .RTM. acetate 1.2 1.06 0.68 Spray viscosity.sup.2 (sec)
28.4 28.2 28.1 Paint temperature (.degree. F.) 73.3 73.5 73.1
Theory % Solids.sup.3 50.8 51.0 51.6 .sup.1Acrylic resin (30%
styrene, 19.9% hydroxyethyl methacrylate, 28.7% CarduraE (available
from Shell Chemical Co.), 9.5% acrylic acid, and 12% ethylhexyl
acrylate) at 65% solids in SOLVESSO 100 (available from Exxon
Chemicals America), prepared in Example A of U.S Pat. No.
5,965,670. .sup.2Viscosity measured in seconds with a #4 FORD
efflux cup at ambient temperature. .sup.3Theory % Solids of a
coating is determined by taking the solid weight of the coating
formulation divided by the sum of the parts by weight of the
coating formulation and the reducing solvent weight
[0255]
7TABLE 2 Ingredient Example 7* Example 8 Example 9 Example 2
pre-mix 93.4 (51.7) 93.4 (51.7) 93.4 (51.7) Example 3 pre-mix 83.3
(56.0) 81.8 (55.0) 77.4 (52.0) Siloxane Borate of -- 1.79 (1.00)
7.1 (4.00) Example D Methyl n-amyl ketone 2.00 -- -- Butyl
Cellosolve .RTM. 2.00 -- -- acetate Butyl Carbitol .RTM. acetate
0.50 -- -- Reduction Information: Methyl n-amyl ketone 3.03 4.7
3.83 Butyl Cellosolve .RTM. 3.03 4.7 3.83 acetate Butyl Carbitol
.RTM. acetate 0.67 1.04 0.85 Spray viscosity.sup.1 (sec) 28.4 28.7
28.1 Paint temperature (.degree. F.) 72.4 72.3 72.0 Theory %
Solids.sup.2 57.3 57.5 57.8 .sup.1Viscosity measured in seconds
with a #4 FORD efflux cup at ambient temperature. .sup.2Theory %
Solids of a coating is determined by taking the solid weight of the
coating formulation divided by the sum of the parts by weight of
the coating formulation and the reducing solvent weight.
Testing
[0256] The film forming compositions of Examples 4-9 were spray
applied to a pigmented basecoat to form color-plus-clear composite
coatings over primed electrocoated steel panels. The panels used
were cold rolled steel panels (size 4 inches.times.12 inches (10.16
cm by 30.48 cm)). The steel panels for Examples 4-6 were coated
with ED5000 electrocoat, available from PPG Industries, Inc, and
SUPERMAR primer, available from Herberts/DuPont. The ED5000
electrocoat test panels are available as APR22986 from ACT
Laboratories, Inc. of Hillsdale, Mich. Examples 7-9 utilized steel
panels that were coated with ED5240 electrocoat and FCP6579 primer,
both available from PPG Industries, Inc. The test panels are
available as APR40017 from ACT Laboratories Inc. of Hillsdale,
Mich.
[0257] The basecoat used for Examples 4-6 was Nero Vulcano UR806/A,
black pigmented solvent-based acrylic/melamine basecoat, available
from PPG Industries, Inc. Examples 7-9 used ODCT6373 Ebony Black, a
black pigmented solvent-based acrylic/melamine basecoat, available
from PPG Industries, Inc.
[0258] The Nero Vulcano UR806/A basecoat was automated spray
applied in one coat to the electrocoated and primed steel panels at
ambient temperature (about 70.degree. F. (21.degree. C.)). A dry
film thickness of about 0.5 to 0.7 mils (about 13 to 18
micrometers) was targeted. After the basecoat application, a ninety
second air flash at ambient temperature was given before applying
the clearcoat. The ODCT6373 Ebony Black basecoat was automated
spray applied in two coats to the electrocoated and primed steel
panels at ambient temperature (about 70.degree. F. (21.degree.
C.)). A ninety second air flash at ambient temperature was given
between the two basecoat applications. A dry film thickness of
about 0.6 to 0.8 mils (about 15 to 20 micrometers) was targeted.
After the second basecoat application, a ninety second air flash at
ambient temperature was given before applying the clearcoat.
[0259] The clear coating compositions of Examples 4-9 were each
automated spray applied to a basecoated panel at ambient
temperature in two coats with a ninety second ambient flash between
applications. Examples 4-6 were targeted for a 1.5 to 1.7 mils
(about 38 to 43 micrometers) dry film thickness, and Examples 7-9
were targeted for a 1.7 to 1.9 mils (about 43 to 48 micrometers)
dry film thickness. All coatings were allowed to air flash at
ambient temperature for ten minutes. Panels prepared from each
coating were baked for thirty minutes at 285.degree. F.
(141.degree. C.) to fully cure the coating(s). The panels were
baked in a horizontal position.
[0260] To test for recoat adhesion, an original basecoated and
clearcoated panel, as described above, was given another layer of
basecoat and clearcoat or clearcoat only. Examples 4-6 were
recoated with Nero Vulcano UR806/A and Examples 4-6, depending on
the respective original panel. Examples 7-9 were recoated with
ODCT6373 Ebony Black and Examples 7-9, depending on the respective
original panel. For example, an Example 4clearcoat over Nero
Vulcano UR806/A original (prepared above) was recoated with Nero
Vulcano UR806/A and Example 4 clearcoat. Half of an original panel
from each clear coating was basecoated and clearcoated and the
other half of the panel was clearcoated only. To recoat the panels
half and half, the bottom halves of the original panels were
covered with aluminum foil and then the respective basecoats were
automated spray applied as described above. The foil was removed,
resulting in an original panel with the upper half coated in
basecoat and the bottom half still with only the original coating
layers. The respective clearcoat was then automated spray applied
to the entire panel as described above. The resulting panels were
half coated in basecoat/ clearcoat from the original spray
application and another layer of basecoat/ clearcoat from the
recoat spray application (B/C//B/C). The other half of the
resulting panel was coated in basecoat/clearcoat from the original
spray application and another layer of clearcoat from the recoat
spray application (B/C//C). Test results for the coatings are
reported below in Table 3.
[0261] As mentioned above the coating compositions of Examples 4-6
were applied over Nero Vulcano UR806/A basecoat and Examples 7-9
were applied over ODCT6373 Ebony Black basecoat.
8TABLE 3 Adhesion Promoter (B) Elemental Windshield Weight %
Adhesion.sup.3 Example on Resin Recoat Adhesion.sup.2 (% cohesive #
Solids 20.degree. Gloss.sup.1 B/C//B/C B/C//C failure) 4* 0 91 0 td
0 td -- 5 0.02 91 2/3 0 -- 6 0.08 91 4+ 4 -- 7* 0 86 2+ 0 0 8 0.02
86 5- 3+ 100 9 0.08 84 5 5 100 .sup.120.degree. gloss was measured
with a Statistical Novo-Gloss 20.degree. gloss meter, available
from Paul N. Gardner Company, Inc. .sup.2Recoat adhesion tests the
adhesion of the recoat layer (either basecoat/clearcoat or
clearcoat only) to the original layers (steel/
electrodeposition/primer/basecoat/clearcoa- t). A multi-blade claw
with 2.0 mm spaced teeth (blade and handle/blade holder are
available from Paul N. Gardner Company, Inc.) was used to scribe
the cured coating. Two sets of scribes were made by scribing the
second set on top of and perpendicular to the first set. Detached
flakes and ribbons of coating were wiped off the panel and
strapping tape (3M #898 available from Minnesota, Mining and
Manufacturing Co. - 3M) was smoothed firmly over the crosshatch
marking. Within 90 seconds of application, the tape was removed in
one continuous motion directed toward the tester and as parallel to
the panel as possible. The scribed area was inspected and rated for
removal of the recoat layer to the substrate according to the
following scale: 5 = The edges of the cuts are completely smooth
and none of the lattice squares is detached. 4 = Small flakes of
coating are detached at intersections. Less than five percent of
the area is affected. 3 = Small flakes of the coating are detached
along edges and at intersections of cuts. The area affected is five
to fifteen percent of the lattice. 2 = The coating has flaked along
the edges and on parts of the squares. The area affected is fifteen
to thirty-five percent of the lattice. 1 = The coating has flaked
along the edges of cuts in large ribbons and whole squares have
detached. The area affected is thirty-five to sixty-five percent of
the lattice. 0 = Flaking and detachment worse than rating 1. Over
sixty-five percent of the lattice is affected. Td = Total
delamination, .sup.3The adhesion between a coating and a windshield
adhesive used in the automotive industry was determined using the
Quick Knife test. Within 1 to 4 hours of the final thirty minute
bake cycle, a bead of the BETASEAL 15625 urethane adhesive
(Supplied by Essex Specialty Products Inc.) was applied to the
surface of the clearcoat of a basecoated and clearcoated panel,
prepared as described above. The plastic nozzle (supplied with
adhesive) was prepared for the urethane by cutting the tip at
.about.80.degree. angle. The opening measured approximately 5 mm in
diameter. On the long end of the cut edge, a notch approximately 5
mm wide by 2 mm high was cut. The tube of urethane was placed in a
battery powered caulking gun and a small amount was squeezed from
the tube into a paper cup for disposal. The caulking gun was set at
.about.90% speed for a steady flow of adhesive. The plastic tip was
placed on the panel with the notch facing away from the person
applying the bead. With the tip held firmly on the panel at the
same angle (80.degree.) as the cut nozzle, a steady bead was
applied down the length of the panel. The bead was flat where it
contacted the panel. After the bead was laid, the panel was placed
in a ventilated hood where it remained undisturbed for at least 72
hours @20-50% relative humidity in order to cure. After the bead
cured, the adhesive bead was cut with a razor blade knife. A small
section was cut at the beginning of the bead to make it easier to
grasp. To cut the bead, the small beginning section was pulled back
at approximately a 180.degree. angle and slices were made in the
adhesive at a 60.degree. to 80.degree. angle in a quick motion. The
blade was kept in contact with the clearcoat at all times during.
The adhesive bead continued to be pulled while the adhesive was
being cut at .about.1/2" intervals. A minimum of 10 cuts was made.
After making slices to the adhesive bead, the panel was rated for %
Cohesive Failure (% C.F.) of the bead to the panel. (Cohesive
Failure occurs when the integrity of the adhesive bead is lost as a
result of cutting and pulling rather than the bond between the
adhesive bead and the clearcoat surface.) Failures were reported as
a total % along the bead. For example, if there was 20% of the
urethane remaining on the panel, then it was reported as 20% C.F.
and if the entire bead can be pulled off, it was considered to be
0% C.F. The desired result was a minimum of 90% or higher
cohesion.
[0262] The data presented above in Table 3 illustrate that recoat
adhesion for the one-package coating compositions of the present
invention improves as the amount of polysiloxane borate increases
in the composition, while similar comparative compositions which do
not contain the polysiloxane borate have poor or no recoat
adhesion. Further, the data illustrate that while the comparative
composition of Example 7 exhibits very poor (0%) windshield
adhesion, the compositions of the present invention (Examples 8 and
9) exhibit excellent (100%) windshield adhesion.
Examples 10 Through 13
[0263] The following Examples 10 through 13 presented in Table 4
below describe the preparation of thermosetting coating
compositions based on epoxy containing acrylic resins cured with
acid functional curing agents in combination with aminoplast
resins. The compositions were prepared by admixing the following
ingredients under mild agitation. Note, those comparative
compositions which do not contain a boron-containing compound
(i.e., Comparative Examples 10 and 13) are designated with an
"*".
9TABLE 4 Example Example Example Example 10* 11 12 13* Solids
Solids Solids Solids Resin Resin Resin Resin + Soln. + Soln. +
Soln. + Soln. Materials Additive Wt. Additive Wt. Additive Wt.
Additive Wt. n-pentyl -- 25 -- 25 -- 25 -- 15 propionate.sup.1
DOWANOL -- -- -- -- -- -- -- 11.2 PM.sup.2 TINUVIN .RTM. -328.sup.3
3 3 3 3 3 3 2.7 2.7 Colloidal silica 10.5 10.5 10.5 -- --
dispersion of Example A 60% GMA 42.9 67 39.05 61 37.05 58 -- --
resin.sup.4 50% GMA -- -- -- -- -- -- 56.25 87.9 resin.sup.5
Primary amyl -- -- -- -- -- -- -- 4.1 alcohol.sup.6 CYMEL 202.sup.7
3 3.8 3 3.8 3 3.8 2.05 2.6 CYLINK .RTM. 10 20 10 20 10 20 -- --
2000.sup.8 fumed silica -- -- -- -- -- -- 12.9 dispersion.sup.9
Isostearic 4 4 4 4 4 4 4.1 4.1 Acid.sup.10 PENTEK.sup.11 34.25 50.4
34.1 50 32.1 47.2 34.2 50.3 Siloxane -- -- 4 8.1 8 16.2 -- --
Borate of Example A TlNUVlN .RTM. 123 0.4 0.4 0.4 0.4 0.4 0.4 0.35
0.35 Polybutyl -- -- -- -- -- -- 0.51 0.85 acrylate OX-60.sup.12 --
-- -- -- -- -- 0.04 0.08 Multiflow (50% 0.025 0.05 0.025 0.05 0.025
0.05 0.09 0.18 soln. of MODAFLOW).sup.1 Di-methyl 0.3 0.3 0.3 0.3
0.3 0.3 0.32 0.32 cocoamine.sup.14 .sup.1Available from Dow
Chemical Co. .sup.2Dipropylene glycol monomethyl ether, available
from Dow Chemical Co. .sup.32-(2'-Hydroxy-3',5'-dtert-amylphenyl)
benzotriazole UV light stabilizer available from Ciba Specialty
Chemicals Corp. .sup.4Acrylic resin comprising 60% glycidyl
methacrylate, 31% n-butyl methacrylate, 0.2% methyl methacrylate,
7% styrene, 2% diphenyl-2,4-methyl-4 pentene-1, 66% solids in
dipropylene glycol monomethyl ether and n-amyl propionate.
.sup.5Acrylic resin comprising 50% glycidyl methacrylate, 41%
n-butyl methacrylate, 0.2% methyl methacrylate, 7% styrene, 2%
diphenyl-2,4-methyl-4 pentene-1, 64% solids in dipropylene glycol
monomethyl ether and n-amyl propionate. .sup.6Available from Dow
Chemical Co. .sup.7Melamine available from Cytec Industries, Inc.
.sup.8Available from Cytec Industries, Inc. .sup.9R-812 silica from
Degussa dispersed in n-amyl alcohol and a trimethylol
propane/methylhexahydrophthalic anhydride half ester of Example G
in U.S. Pat. No. 5,256,452. .sup.10Available from Uniqema.
.sup.11Polyester prepared from 83% 4-methyl hexahydrophthalic
anhydride and 17% pentaerythritol, 67% solids in n-propyl alcohol
and n-amyl propionate. .sup.12Available from Kusumoto, a King
Industries distributor. .sup.13Available from Solutia.
.sup.14Available from Albemarle Corp.
[0264] The clearcoats prepared as described above were reduced with
DOWANOL.RTM. DPM to a spray viscosity of 26 seconds at ambient
temperature (approximately 76.degree. F. (26.degree. C.)), with a
Ford #4 cup.
[0265] Testing
[0266] The film forming compositions of Examples 10-13 were spray
applied to a pigmented basecoat to form color-plus-clear composite
coatings over electrocoated steel panels. The panels used were cold
rolled steel panels (size 4 inches.times.12 inches (10.16 cm by
30.48 cm)). The steel panels for Examples 10-13 were coated with
ED5000 electrocoat, available from PPG Industries, Inc. These
prepared test panels are available as APR23884 from ACT
Laboratories, Inc. of Hillsdale, Mich.
[0267] The basecoat used for Examples 10-13 was HWB-9517, black
pigmented waterborne basecoat, available from PPG Industries, Inc.
The HWB-9517 basecoat was automated spray applied in one coat to
the electrocoated steel panels at ambient temperature (i.e., at
approximately 76.degree. F. (25.degree. C.) and 30% relative
humidity). A dry film thickness of about 0.5 to 0.7 mils (about 13
to 18 micrometers) was targeted. The basecoat was allowed to flash
ambiently for about 5minutes and then prebaked for five minutes at
200.degree. F. (93.degree. C.).
[0268] The clear coating compositions of Examples 10-13 were each
automated spray applied to a basecoated panel at ambient
temperature in two coats with a 60 second ambient flash between
applications. Coatings of Examples 10-13 were targeted for a 1.8 to
2 mils (about 46 to 51 micrometers) dry film thickness. All
coatings were allowed to air flash at ambient temperature for ten
minutes. Panels prepared from each coating were baked for thirty
minutes at 285.degree. F. (141.degree. C.) to fully cure the
coating(s). The panels were baked in a horizontal position.
[0269] To test for recoat adhesion, an original basecoated and
clearcoated panel, as described above, was given another layer of
basecoat and clearcoat or clearcoat only. Examples 10-13 were
recoated with HWB-9517 basecoat. To recoat the panels half and
half, the right halves of the original panels were covered with
masking tape and then the respective basecoats were automated spray
applied as described above. The tape was removed, resulting in an
original panel with the right half coated in basecoat and the left
half still with only the original coating layers. The respective
clearcoat was then automated spray applied to the entire panel as
described above. The resulting panels were half coated in
basecoat/clearcoat from the original spray application and another
layer of basecoat/clearcoat from the recoat spray application
(B/C//B/C). The other half of the resulting panel was coated in
basecoat/clearcoat from the original spray application and another
layer of clearcoat from the recoat spray application (B/C//C). Test
data is presented below in the following Table 5.
10TABLE 5 Elemental MVSS Recoat Recoat weight % primerless Adhesion
Adhesion Clearcoat 20.degree. on resin adhesion % pass % pass
composition Gloss solids % pass B/C//B/C B/C//C Example 11 72 0.08
data 30 50 unavailable Example 12 72 0.16 88 100 100 Example 10* 83
0 100 0 0 Example 13* 83 0 100 100 100 *Comparative examples
[0270] The data presented in Table 5 above illustrate that the
epoxy-acid clear coat controls of Comparative Examples 10 and 13
pass MVSS primeness adhesion. However, these same the clearcoating
of Example 10 exhibits very poor recoat adhesion when recoated
either with a subsequently applied repair basecoat/clearcoat system
or a repair clearcoat. By contrast, the coating compositions of the
present invention which contain the polysiloxane borate, exhibit
improved recoat adhesion and 100% recoat adhesion (see Examples 11
and 12, respectively).
Two-component Coating Compositions Comparative Example 14
[0271] This comparative example describes the preparation of a
two-component clearcoat composition which does not contain an
adhesion promoting compound. The coating composition was prepared
by admixing the following ingredients sequentially under mild
agitation.
11 Parts by Weight Solid Weight Ingredient (grams) (grams) Methyl
n-amyl ketone 30.0 -- Butyl Cellosolve .RTM. acetate 10.0 -- Butyl
Carbitol .RTM. acetate 5.0 -- Tinuvin 928 3.0 3.0 Tinuvin 292 0.5
0.5 Silica dispersion of Example A 8.8 6.7 Acrylic Resin.sup.1 58.2
42.2 CYMEL .RTM. 202 18.8 15.0 Polysiloxane polyol of Example AA
11.0 11.0 Phenyl Acid Phosphate Catalyst.sup.2 0.7 0.5 Desmodur
N3300.sup.4 27.1 27.1 .sup.1Acrylic polyol prepared from 14.5%
butyl acrylate, 14.5% butyl methacrylate, 27.6% isobornyl
methacrylate, 22.6% hydroxypropyl methacrylate, 20.4% hydroxyethyl
methacrylate, and 0.4% acrylic acid, having resin solids of 69.7%,
Mw 3227 and a hydroxyl value of 101. .sup.2Phenyl acid phosphate
solution, 75 percent in isopropanol. .sup.3Isocyanurate of
hexamethylene diisocyanate available from Bayer Corp.
Example 15
[0272] This example describes the preparation of a two-component
clearcoat composition of the present invention which contains a
siloxane borate as an adhesion promoting compound. The coating
composition was prepared by admixing the following ingredients
sequentially under mild agitation.
12 Parts by Weight Solid Weight Ingredient (grams) (grams) Methyl
n-amyl ketone 30.0 -- Butyl Cellosolve .RTM. acetate 10.0 -- Butyl
Carbitol .RTM. acetate 5.0 -- Tinuvin 928 3.0 3.0 Tinuvin 292 0.5
0.5 Silica dispersion of Example A 8.8 6.7 Acrylic Resin of Example
14 58.2 42.2 Cymel 202 18.8 15.0 Polysiloxane polyol of Example AA
10.0 10.0 Siloxane Borate of Example E 2.4 1.0 Phenyl Acid
Phosphate Catalyst 0.7 0.5 Desmodur N3300 27.1 27.1
Example 16
[0273] This example describes the preparation of a two-component
clearcoat composition of the present invention which contains a
siloxane borate as an adhesion promoting compound. The coating
composition was prepared by admixing the following ingredients
sequentially under mild agitation.
13 Parts by Weight Solid Weight Ingredient (grams) (grams) Methyl
n-amyl ketone 30.0 -- Butyl Cellosolve .RTM. acetate 10.0 -- Butyl
Carbitol .RTM. acetate 5.0 -- Tinuvin 928 3.0 3.0 Tinuvin 292 0.5
0.5 Silica dipersion of Example A 8.8 6.7 Acrylic Resin of Example
14 58.2 42.2 Cymel 202 18.8 15.0 Polysiloxane polyol of Example AA
9.0 9.0 Siloxane Borate of Example E 4.9 2.0 Phenyl Acid Phosphate
Catalyst 0.7 0.5 Desmodur N3300 27.1 27.1
Example 17
[0274] This example describes the preparation of a two-component
clearcoat composition of the present invention which contains a
siloxane borate as an adhesion promoting compound. The coating
composition was prepared by admixing the following ingredients
sequentially under mild agitation.
14 Parts by Weight Solid Weight Ingredient (grams) (grams) Methyl
n-amyl ketone 30.0 -- Butyl Cellosolve .RTM. acetate 10.0 -- Butyl
Carbitol .RTM. acetate 5.0 -- Tinuvin 928 3.0 3.0 Tinuvin 292 0.5
0.5 Silica dispersion of Example A 8.8 6.7 Acrylic Resin of Example
14 58.2 42.2 Cymel 202 18.8 15.0 Polysiloxane polyol of Example AA
7.0 7.0 Siloxane Borate of Example E 9.8 4.0 Phenyl Acid Phosphate
Catalyst 0.7 0.5 DesmodurN3300 27.1 27.1
Example 18
[0275] This example describes the preparation of a two-component
clearcoat composition of the present invention which contains a
boric acid as an adhesion promoting compound. The coating
composition was prepared by admixing the following ingredients
sequentially under mild agitation.
15 Parts by Weight Solid Weight Ingredient (grams) (grams) Methyl
n-amyl ketone 30.0 -- Butyl Cellosolve .RTM. acetate 10.0 -- Butyl
Carbitol .RTM. acetate 5.0 -- Tinuvin 928 3.0 3.0 Tinuvin 292 0.5
0.5 Silica dispersion of Example A 8.8 6.7 Acrylic Resin of Example
14 58.2 42.2 Cymel 202 18.8 15.0 Polysiloxane polyol of Example AA
11.0 11.0 Boric acid (20% solution in methanol) 1.3 0.3 Phenyl Acid
Phosphate Catalyst 0.7 0.5 DesmodurN3300 27.1 27.1
Example 19
[0276] This example describes the preparation of a two-component
clearcoat composition of the present invention which contains a
boric acid as an adhesion promoting compound. The coating
composition was prepared by admixing the following ingredients
sequentially under mild agitation.
16 Parts by Weight Solid Weight Ingredient (grams) (grams) Methyl
n-amyl ketone 30.0 -- Butyl Cellosolve .RTM. acetate 10.0 -- Butyl
Carbitol .RTM. acetate 5.0 -- Tinuvin 928 3.0 3.0 Tinuvin 292 0.5
0.5 Silica dispersion of Example A 8.8 6.7 Acrylic Resin of Example
14 58.2 42.2 Cymel 202 18.8 15.0 Polysiloxane polyol of Example AA
11.0 11.0 Boric acid (20% solution in methanol) 5.0 1.0 Phenyl Acid
Phosphate Catalyst 0.7 0.5 DesmodurN3300 27.1 27.1
Example 20
[0277] This example describes the preparation of a two-component
clearcoat composition of the present invention which contains
triisopropyl borate as an adhesion promoting compound. The coating
composition was prepared by admixing the following ingredients
sequentially under mild agitation.
17 Parts by Weight Solid Weight Ingredient (grams) (grams) Methyl
n-amyl ketone 30.0 -- Butyl Cellosolve .RTM. acetate 10.0 -- Butyl
Carbitol .RTM. acetate 5.0 -- Tinuvin 928 3.0 3.0 Tinuvin 292 0.5
0.5 Silica dispersion of Example A 8.8 6.7 Acrylic Resin of Example
14 58.2 42.2 Cymel 202 18.8 15.0 Polysiloxane polyol of Example AA
11.0 11.0 Triisopropyl Borate.sup.1 0.9 0.9 Phenyl Acid Phosphate
Catalyst 0.7 0.5 DesmodurN3300 27.1 27.1 .sup.1Available from
Aldrich Chemical Co.
Example 21
[0278] This example describes the preparation of a two-component
clearcoat composition of the present invention which contains
DOWANOL PM borate as an adhesion promoting compound. The coating
composition was prepared by admixing the following ingredients
sequentially under mild agitation.
18 Parts by Weight Solid Weight Ingredient (grams) (grams) Methyl
n-amyl ketone 30.0 -- Butyl Cellosolve .RTM. acetate 10.0 -- Butyl
Carbitol .RTM. acetate 5.0 -- Tinuvin 928 3.0 3.0 Tinuvin 292 0.5
0.5 Silica dispersion of Example A 8.8 6.7 Acrylic Resin of Example
14 58.2 42.2 Cymel 202 18.8 15.0 Polysiloxane polyol of Example AA
11.0 11.0 Dowanol PM borate of Example F 2.2 0.3 Phenyl Acid
Phosphate Catalyst 0.7 0.5 DesmodurN3300 27.1 27.1
Example 22
[0279] This example describes the preparation of a two-component
clearcoat composition of the present invention which contains an
acrylic borate as an adhesion promoting compound. The coating
composition was prepared by admixing the following ingredients
sequentially under mild agitation.
19 Parts by Weight Solid Weight Ingredient (grams) (grams) Methyl
n-amyl ketone 30.0 -- Butyl Cellosolve .RTM. acetate 10.0 -- Butyl
Carbitol .RTM. acetate 5.0 -- Tinuvin 928 3.0 3.0 Tinuvin 292 0.5
0.5 Silica dispersion of Example A 8.8 6.7 Acrylic Borate of
Example G 60.9 42.2 Cymel 202 18.8 15.0 Polysiloxane polyol of
Example AA 11.0 11.0 Phenyl Acid Phosphate Catalyst 0.7 0.5
DesmodurN3300 27.1 27.1
Example 23
[0280] This example describes the preparation of a two-component
clearcoat composition of the present invention which contains a
siloxane aluminum isopropoxide as an adhesion promoting compound.
The coating composition was prepared by admixing the following
ingredients sequentially under mild agitation.
20 Parts by Weight Solid Weight Ingredient (grams) (grams) Methyl
n-amyl ketone 30.0 -- Butyl Cellosolve .RTM. acetate 10.0 -- Butyl
Carbitol .RTM. acetate 5.0 -- Tinuvin 928 3.0 3.0 Tinuvin 292 0.5
0.5 Silica dispersion of Example A 8.8 6.7 Acrylic Resin of Example
14 58.2 42.2 Cymel 202 18.8 15.0 Polysiloxane polyol of Example AA
-- -- Siloxane Aluminum isopropoxide of 42.9 22.9 Example H Phenyl
Acid Phosphate Catalyst 0.7 0.5 DesmodurN3300 27.1 27.1
[0281] The clearcoats Examples 14 through 23 described above were
reduced in viscosity to about 25 seconds on a #4 Ford efflux cup at
ambient temperature using methyl n-amyl ketone.
Testing
[0282] The film forming compositions of Examples 14-23 were spray
applied to a pigmented basecoat to form color-plus-clear composite
coatings over primed electrocoated steel panels. The panels used
were cold rolled steel panels (size 4 inches.times.12 inches (10.16
cm by 30.48 cm)). The steel panels for Examples 14-23 were coated
with ED5050B electrocoat, available from PPG Industries, Inc, and
1177225A primer surfacer, also available from PPG Industries, Inc
or coated with ED5000 electrocoat, available from PPG Industries,
Inc, and GPXH5379 primer surfacer, also available from PPG
Industries, Inc. The test panels are available as APR39754 or
APR39375 from ACT Laboratories, Inc. of Hillsdale, Mich.
[0283] The basecoat used for Examples 14-23 was Obsidian Schwarz,
black pigmented waterborne basecoat, available from BASF
Corporation. The Obsidian Schwarz basecoat was automated spray
applied in two coats with approximately 30 second flash between
coats to the electrocoated and primed steel panels at about
70.degree. F. (21.degree. C.) temperature and about 60% relative
humidity. A dry film thickness of about 0.5 to 0.6 mils (about 12
to 16 micrometers) was targeted. The basecoat was allowed to flash
ambiently for about five minutes and then prebaked for five minutes
at 176.degree. F. (80.degree. C.).
[0284] The clear coating compositions of Examples 14-23 were each
automated spray applied to a basecoated panel at ambient
temperature in two coats with about a 30 second ambient flash
between coats. Examples 1-10 were targeted for a 1.5 to 2.0 mils
(about 38 to 51 micrometers) dry film thickness. All coatings were
allowed to air flash at ambient temperature for ten minutes. Panels
prepared from each coating were baked for 30 minutes at 285.degree.
F. (141.degree. C.) to fully cure the coating(s). The panels were
baked in a horizontal position.
[0285] To test for recoat adhesion, an original basecoated and
clearcoated panel, as described above, was given another layer of
basecoat and clearcoat or clearcoat only. With the condition of
sanding, the right half of the panel was sanded with 1200 grit sand
paper and the left half was not sanded thus giving sanded and
non-sanded areas. Half of an original panel from each clear coating
was basecoated and clearcoated and the other half of the panel was
clearcoated only. To recoat the panels half and half, the bottom
halves of the original panels were covered with aluminum foil and
then the top halves were recoated with Obsidian Schwarz basecoat
using the same conditions as above. The foil was removed, resulting
in an original panel with the upper half coated in basecoat and the
bottom half still with only the original coating layers. The
respective clearcoat was then automated spray applied to the entire
panel as described above. The resulting panels were half coated in
basecoat/clearcoat from the original spray application and another
layer of basecoat/ clearcoat from the recoat spray application
(B/C//B/C). The other half of the resulting panel was coated in
basecoat clearcoat from the original spray application and another
layer of clearcoat from the recoat spray application (B/C//C). Test
data is reported below in the following Table 6.
21TABLE 6 Adhesion promoter Recoat Adhesion - Cross Hatch Elemental
30/285.degree. F. // 30/285.degree. F. Weight % Sanded Non-Sanded
on resin B/C// B/C// B/C// B/C// Example # solids 20.degree. Gloss
B/C C B/C C 14* 0 84 5 5 0 0 15 0.02 84 5 5 5 0 16 0.04 85 5 5 5 0
17 0.08 84 5 5 5 5- 18 0.04 84 5 5 5 0 19 0.16 85 5 5 5 5- 20 0.04
85 -- -- 5 0 21 0.04 85 -- -- 5 0 22 0.03 85 -- -- 5 0 23 0.10 82 5
5 5 0 *Designates a comparative example.
[0286] The data presented above in Table 6 illustrate that the
inclusion in a two-component clearcoating composition of the
adhesion promoting composition of Examples C through H above
provide excellent adhesion where a basecoat/clearcoat system is
recoated with a repair basecoat/clearcoat system. Further, the data
for Examples 14-22 illustrate that the inclusion of the
polysiloxane borate and boric acid (where the composition also
comprises a polysiloxane) at levels of elemental boron of 0.08 or
greater, show excellent adhesion where a basecoat/clearcoat system
is repaired with a clearcoat.
[0287] It will be appreciated by those skilled in the art that
changes could be made to the embodiments described above without
departing from the broad inventive concept thereof. It is
understood, therefore, that this invention is not limited to the
particular embodiments disclosed, but it is intended to cover
modifications which are within the spirit and scope of the
invention, as defined by the appended claims.
* * * * *